https://leetcode.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition/
1498. Number of Subsequences That Satisfy the Given Sum Condition
Medium
2.1K
188
Companies
You are given an array of integers nums and an integer target.
Return the number of non-empty subsequences of nums such that the sum of the minimum and maximum element on it is less or equal to target. Since the answer may be too large, return it modulo 109 + 7.
Example 1:
Input: nums = [3,5,6,7], target = 9
Output: 4
Explanation: There are 4 subsequences that satisfy the condition.
[3] -> Min value + max value <= target (3 + 3 <= 9)
[3,5] -> (3 + 5 <= 9)
[3,5,6] -> (3 + 6 <= 9)
[3,6] -> (3 + 6 <= 9)
Example 2:
Input: nums = [3,3,6,8], target = 10
Output: 6
Explanation: There are 6 subsequences that satisfy the condition. (nums can have repeated numbers).
[3] , [3] , [3,3], [3,6] , [3,6] , [3,3,6]
Example 3:
Input: nums = [2,3,3,4,6,7], target = 12
Output: 61
Explanation: There are 63 non-empty subsequences, two of them do not satisfy the condition ([6,7], [7]).
Number of valid subsequences (63 - 2 = 61).
Constraints:
1 <= nums.length <= 105
1 <= nums[i] <= 106
1 <= target <= 106
1498. Number of Subsequences That Satisfy the Given Sum Condition
Medium
2.1K
188
Companies
You are given an array of integers nums and an integer target.
Return the number of non-empty subsequences of nums such that the sum of the minimum and maximum element on it is less or equal to target. Since the answer may be too large, return it modulo 109 + 7.
Example 1:
Input: nums = [3,5,6,7], target = 9
Output: 4
Explanation: There are 4 subsequences that satisfy the condition.
[3] -> Min value + max value <= target (3 + 3 <= 9)
[3,5] -> (3 + 5 <= 9)
[3,5,6] -> (3 + 6 <= 9)
[3,6] -> (3 + 6 <= 9)
Example 2:
Input: nums = [3,3,6,8], target = 10
Output: 6
Explanation: There are 6 subsequences that satisfy the condition. (nums can have repeated numbers).
[3] , [3] , [3,3], [3,6] , [3,6] , [3,3,6]
Example 3:
Input: nums = [2,3,3,4,6,7], target = 12
Output: 61
Explanation: There are 63 non-empty subsequences, two of them do not satisfy the condition ([6,7], [7]).
Number of valid subsequences (63 - 2 = 61).
Constraints:
1 <= nums.length <= 105
1 <= nums[i] <= 106
1 <= target <= 106
LeetCode
Number of Subsequences That Satisfy the Given Sum Condition - LeetCode
Can you solve this real interview question? Number of Subsequences That Satisfy the Given Sum Condition - You are given an array of integers nums and an integer target.
Return the number of non-empty subsequences of nums such that the sum of the minimum…
Return the number of non-empty subsequences of nums such that the sum of the minimum…
https://leetcode.com/problems/find-the-longest-valid-obstacle-course-at-each-position/
1964. Find the Longest Valid Obstacle Course at Each Position
Hard
573
17
Companies
You want to build some obstacle courses. You are given a 0-indexed integer array obstacles of length n, where obstacles[i] describes the height of the ith obstacle.
For every index i between 0 and n - 1 (inclusive), find the length of the longest obstacle course in obstacles such that:
You choose any number of obstacles between 0 and i inclusive.
You must include the ith obstacle in the course.
You must put the chosen obstacles in the same order as they appear in obstacles.
Every obstacle (except the first) is taller than or the same height as the obstacle immediately before it.
Return an array ans of length n, where ans[i] is the length of the longest obstacle course for index i as described above.
Example 1:
Input: obstacles = [1,2,3,2]
Output: [1,2,3,3]
Explanation: The longest valid obstacle course at each position is:
- i = 0: [1], [1] has length 1.
- i = 1: [1,2], [1,2] has length 2.
- i = 2: [1,2,3], [1,2,3] has length 3.
- i = 3: [1,2,3,2], [1,2,2] has length 3.
Example 2:
Input: obstacles = [2,2,1]
Output: [1,2,1]
Explanation: The longest valid obstacle course at each position is:
- i = 0: [2], [2] has length 1.
- i = 1: [2,2], [2,2] has length 2.
- i = 2: [2,2,1], [1] has length 1.
Example 3:
Input: obstacles = [3,1,5,6,4,2]
Output: [1,1,2,3,2,2]
Explanation: The longest valid obstacle course at each position is:
- i = 0: [3], [3] has length 1.
- i = 1: [3,1], [1] has length 1.
- i = 2: [3,1,5], [3,5] has length 2. [1,5] is also valid.
- i = 3: [3,1,5,6], [3,5,6] has length 3. [1,5,6] is also valid.
- i = 4: [3,1,5,6,4], [3,4] has length 2. [1,4] is also valid.
- i = 5: [3,1,5,6,4,2], [1,2] has length 2.
Constraints:
n == obstacles.length
1 <= n <= 105
1 <= obstacles[i] <= 107
1964. Find the Longest Valid Obstacle Course at Each Position
Hard
573
17
Companies
You want to build some obstacle courses. You are given a 0-indexed integer array obstacles of length n, where obstacles[i] describes the height of the ith obstacle.
For every index i between 0 and n - 1 (inclusive), find the length of the longest obstacle course in obstacles such that:
You choose any number of obstacles between 0 and i inclusive.
You must include the ith obstacle in the course.
You must put the chosen obstacles in the same order as they appear in obstacles.
Every obstacle (except the first) is taller than or the same height as the obstacle immediately before it.
Return an array ans of length n, where ans[i] is the length of the longest obstacle course for index i as described above.
Example 1:
Input: obstacles = [1,2,3,2]
Output: [1,2,3,3]
Explanation: The longest valid obstacle course at each position is:
- i = 0: [1], [1] has length 1.
- i = 1: [1,2], [1,2] has length 2.
- i = 2: [1,2,3], [1,2,3] has length 3.
- i = 3: [1,2,3,2], [1,2,2] has length 3.
Example 2:
Input: obstacles = [2,2,1]
Output: [1,2,1]
Explanation: The longest valid obstacle course at each position is:
- i = 0: [2], [2] has length 1.
- i = 1: [2,2], [2,2] has length 2.
- i = 2: [2,2,1], [1] has length 1.
Example 3:
Input: obstacles = [3,1,5,6,4,2]
Output: [1,1,2,3,2,2]
Explanation: The longest valid obstacle course at each position is:
- i = 0: [3], [3] has length 1.
- i = 1: [3,1], [1] has length 1.
- i = 2: [3,1,5], [3,5] has length 2. [1,5] is also valid.
- i = 3: [3,1,5,6], [3,5,6] has length 3. [1,5,6] is also valid.
- i = 4: [3,1,5,6,4], [3,4] has length 2. [1,4] is also valid.
- i = 5: [3,1,5,6,4,2], [1,2] has length 2.
Constraints:
n == obstacles.length
1 <= n <= 105
1 <= obstacles[i] <= 107
LeetCode
Find the Longest Valid Obstacle Course at Each Position - LeetCode
Can you solve this real interview question? Find the Longest Valid Obstacle Course at Each Position - You want to build some obstacle courses. You are given a 0-indexed integer array obstacles of length n, where obstacles[i] describes the height of the ith…
https://leetcode.com/problems/matrix-diagonal-sum/
1572. Matrix Diagonal Sum
Easy
2.2K
29
Companies
Given a square matrix mat, return the sum of the matrix diagonals.
Only include the sum of all the elements on the primary diagonal and all the elements on the secondary diagonal that are not part of the primary diagonal.
Example 1:
Input: mat = [[1,2,3],
[4,5,6],
[7,8,9]]
Output: 25
Explanation: Diagonals sum: 1 + 5 + 9 + 3 + 7 = 25
Notice that element mat[1][1] = 5 is counted only once.
Example 2:
Input: mat = [[1,1,1,1],
[1,1,1,1],
[1,1,1,1],
[1,1,1,1]]
Output: 8
Example 3:
Input: mat = [[5]]
Output: 5
Constraints:
n == mat.length == mat[i].length
1 <= n <= 100
1 <= mat[i][j] <= 100
1572. Matrix Diagonal Sum
Easy
2.2K
29
Companies
Given a square matrix mat, return the sum of the matrix diagonals.
Only include the sum of all the elements on the primary diagonal and all the elements on the secondary diagonal that are not part of the primary diagonal.
Example 1:
Input: mat = [[1,2,3],
[4,5,6],
[7,8,9]]
Output: 25
Explanation: Diagonals sum: 1 + 5 + 9 + 3 + 7 = 25
Notice that element mat[1][1] = 5 is counted only once.
Example 2:
Input: mat = [[1,1,1,1],
[1,1,1,1],
[1,1,1,1],
[1,1,1,1]]
Output: 8
Example 3:
Input: mat = [[5]]
Output: 5
Constraints:
n == mat.length == mat[i].length
1 <= n <= 100
1 <= mat[i][j] <= 100
LeetCode
Matrix Diagonal Sum - LeetCode
Can you solve this real interview question? Matrix Diagonal Sum - Given a square matrix mat, return the sum of the matrix diagonals.
Only include the sum of all the elements on the primary diagonal and all the elements on the secondary diagonal that are…
Only include the sum of all the elements on the primary diagonal and all the elements on the secondary diagonal that are…
https://leetcode.com/problems/spiral-matrix/
54. Spiral Matrix
Medium
11.3K
1K
Companies
Given an m x n matrix, return all elements of the matrix in spiral order.
Example 1:
Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [1,2,3,6,9,8,7,4,5]
Example 2:
Input: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
Output: [1,2,3,4,8,12,11,10,9,5,6,7]
Constraints:
m == matrix.length
n == matrix[i].length
1 <= m, n <= 10
-100 <= matrix[i][j] <= 100
54. Spiral Matrix
Medium
11.3K
1K
Companies
Given an m x n matrix, return all elements of the matrix in spiral order.
Example 1:
Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [1,2,3,6,9,8,7,4,5]
Example 2:
Input: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
Output: [1,2,3,4,8,12,11,10,9,5,6,7]
Constraints:
m == matrix.length
n == matrix[i].length
1 <= m, n <= 10
-100 <= matrix[i][j] <= 100
LeetCode
Spiral Matrix - LeetCode
Can you solve this real interview question? Spiral Matrix - Given an m x n matrix, return all elements of the matrix in spiral order.
Example 1:
[https://assets.leetcode.com/uploads/2020/11/13/spiral1.jpg]
Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]…
Example 1:
[https://assets.leetcode.com/uploads/2020/11/13/spiral1.jpg]
Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]…
https://leetcode.com/problems/spiral-matrix-ii/
59. Spiral Matrix II
Medium
5K
215
Companies
Given a positive integer n, generate an n x n matrix filled with elements from 1 to n2 in spiral order.
Example 1:
Input: n = 3
Output: [[1,2,3],[8,9,4],[7,6,5]]
Example 2:
Input: n = 1
Output: [[1]]
Constraints:
1 <= n <= 20
59. Spiral Matrix II
Medium
5K
215
Companies
Given a positive integer n, generate an n x n matrix filled with elements from 1 to n2 in spiral order.
Example 1:
Input: n = 3
Output: [[1,2,3],[8,9,4],[7,6,5]]
Example 2:
Input: n = 1
Output: [[1]]
Constraints:
1 <= n <= 20
https://leetcode.com/problems/uncrossed-lines/
1035. Uncrossed Lines
Medium
2.2K
30
Companies
You are given two integer arrays nums1 and nums2. We write the integers of nums1 and nums2 (in the order they are given) on two separate horizontal lines.
We may draw connecting lines: a straight line connecting two numbers nums1[i] and nums2[j] such that:
nums1[i] == nums2[j], and
the line we draw does not intersect any other connecting (non-horizontal) line.
Note that a connecting line cannot intersect even at the endpoints (i.e., each number can only belong to one connecting line).
Return the maximum number of connecting lines we can draw in this way.
Example 1:
Input: nums1 = [1,4,2], nums2 = [1,2,4]
Output: 2
Explanation: We can draw 2 uncrossed lines as in the diagram.
We cannot draw 3 uncrossed lines, because the line from nums1[1] = 4 to nums2[2] = 4 will intersect the line from nums1[2]=2 to nums2[1]=2.
Example 2:
Input: nums1 = [2,5,1,2,5], nums2 = [10,5,2,1,5,2]
Output: 3
Example 3:
Input: nums1 = [1,3,7,1,7,5], nums2 = [1,9,2,5,1]
Output: 2
Constraints:
1 <= nums1.length, nums2.length <= 500
1 <= nums1[i], nums2[j] <= 2000
1035. Uncrossed Lines
Medium
2.2K
30
Companies
You are given two integer arrays nums1 and nums2. We write the integers of nums1 and nums2 (in the order they are given) on two separate horizontal lines.
We may draw connecting lines: a straight line connecting two numbers nums1[i] and nums2[j] such that:
nums1[i] == nums2[j], and
the line we draw does not intersect any other connecting (non-horizontal) line.
Note that a connecting line cannot intersect even at the endpoints (i.e., each number can only belong to one connecting line).
Return the maximum number of connecting lines we can draw in this way.
Example 1:
Input: nums1 = [1,4,2], nums2 = [1,2,4]
Output: 2
Explanation: We can draw 2 uncrossed lines as in the diagram.
We cannot draw 3 uncrossed lines, because the line from nums1[1] = 4 to nums2[2] = 4 will intersect the line from nums1[2]=2 to nums2[1]=2.
Example 2:
Input: nums1 = [2,5,1,2,5], nums2 = [10,5,2,1,5,2]
Output: 3
Example 3:
Input: nums1 = [1,3,7,1,7,5], nums2 = [1,9,2,5,1]
Output: 2
Constraints:
1 <= nums1.length, nums2.length <= 500
1 <= nums1[i], nums2[j] <= 2000
LeetCode
Uncrossed Lines - LeetCode
Can you solve this real interview question? Uncrossed Lines - You are given two integer arrays nums1 and nums2. We write the integers of nums1 and nums2 (in the order they are given) on two separate horizontal lines.
We may draw connecting lines: a straight…
We may draw connecting lines: a straight…
https://leetcode.com/problems/solving-questions-with-brainpower/
2140. Solving Questions With Brainpower
Medium
956
24
Companies
You are given a 0-indexed 2D integer array questions where questions[i] = [pointsi, brainpoweri].
The array describes the questions of an exam, where you have to process the questions in order (i.e., starting from question 0) and make a decision whether to solve or skip each question. Solving question i will earn you pointsi points but you will be unable to solve each of the next brainpoweri questions. If you skip question i, you get to make the decision on the next question.
For example, given questions = [[3, 2], [4, 3], [4, 4], [2, 5]]:
If question 0 is solved, you will earn 3 points but you will be unable to solve questions 1 and 2.
If instead, question 0 is skipped and question 1 is solved, you will earn 4 points but you will be unable to solve questions 2 and 3.
Return the maximum points you can earn for the exam.
Example 1:
Input: questions = [[3,2],[4,3],[4,4],[2,5]]
Output: 5
Explanation: The maximum points can be earned by solving questions 0 and 3.
- Solve question 0: Earn 3 points, will be unable to solve the next 2 questions
- Unable to solve questions 1 and 2
- Solve question 3: Earn 2 points
Total points earned: 3 + 2 = 5. There is no other way to earn 5 or more points.
Example 2:
Input: questions = [[1,1],[2,2],[3,3],[4,4],[5,5]]
Output: 7
Explanation: The maximum points can be earned by solving questions 1 and 4.
- Skip question 0
- Solve question 1: Earn 2 points, will be unable to solve the next 2 questions
- Unable to solve questions 2 and 3
- Solve question 4: Earn 5 points
Total points earned: 2 + 5 = 7. There is no other way to earn 7 or more points.
Constraints:
1 <= questions.length <= 105
questions[i].length == 2
1 <= pointsi, brainpoweri <= 105
2140. Solving Questions With Brainpower
Medium
956
24
Companies
You are given a 0-indexed 2D integer array questions where questions[i] = [pointsi, brainpoweri].
The array describes the questions of an exam, where you have to process the questions in order (i.e., starting from question 0) and make a decision whether to solve or skip each question. Solving question i will earn you pointsi points but you will be unable to solve each of the next brainpoweri questions. If you skip question i, you get to make the decision on the next question.
For example, given questions = [[3, 2], [4, 3], [4, 4], [2, 5]]:
If question 0 is solved, you will earn 3 points but you will be unable to solve questions 1 and 2.
If instead, question 0 is skipped and question 1 is solved, you will earn 4 points but you will be unable to solve questions 2 and 3.
Return the maximum points you can earn for the exam.
Example 1:
Input: questions = [[3,2],[4,3],[4,4],[2,5]]
Output: 5
Explanation: The maximum points can be earned by solving questions 0 and 3.
- Solve question 0: Earn 3 points, will be unable to solve the next 2 questions
- Unable to solve questions 1 and 2
- Solve question 3: Earn 2 points
Total points earned: 3 + 2 = 5. There is no other way to earn 5 or more points.
Example 2:
Input: questions = [[1,1],[2,2],[3,3],[4,4],[5,5]]
Output: 7
Explanation: The maximum points can be earned by solving questions 1 and 4.
- Skip question 0
- Solve question 1: Earn 2 points, will be unable to solve the next 2 questions
- Unable to solve questions 2 and 3
- Solve question 4: Earn 5 points
Total points earned: 2 + 5 = 7. There is no other way to earn 7 or more points.
Constraints:
1 <= questions.length <= 105
questions[i].length == 2
1 <= pointsi, brainpoweri <= 105
LeetCode
Solving Questions With Brainpower - LeetCode
Can you solve this real interview question? Solving Questions With Brainpower - You are given a 0-indexed 2D integer array questions where questions[i] = [pointsi, brainpoweri].
The array describes the questions of an exam, where you have to process the…
The array describes the questions of an exam, where you have to process the…
https://leetcode.com/problems/count-ways-to-build-good-strings/
2466. Count Ways To Build Good Strings
Medium
457
37
Companies
Given the integers zero, one, low, and high, we can construct a string by starting with an empty string, and then at each step perform either of the following:
Append the character '0' zero times.
Append the character '1' one times.
This can be performed any number of times.
A good string is a string constructed by the above process having a length between low and high (inclusive).
Return the number of different good strings that can be constructed satisfying these properties. Since the answer can be large, return it modulo 109 + 7.
Example 1:
Input: low = 3, high = 3, zero = 1, one = 1
Output: 8
Explanation:
One possible valid good string is "011".
It can be constructed as follows: "" -> "0" -> "01" -> "011".
All binary strings from "000" to "111" are good strings in this example.
Example 2:
Input: low = 2, high = 3, zero = 1, one = 2
Output: 5
Explanation: The good strings are "00", "11", "000", "110", and "011".
Constraints:
1 <= low <= high <= 105
1 <= zero, one <= low
2466. Count Ways To Build Good Strings
Medium
457
37
Companies
Given the integers zero, one, low, and high, we can construct a string by starting with an empty string, and then at each step perform either of the following:
Append the character '0' zero times.
Append the character '1' one times.
This can be performed any number of times.
A good string is a string constructed by the above process having a length between low and high (inclusive).
Return the number of different good strings that can be constructed satisfying these properties. Since the answer can be large, return it modulo 109 + 7.
Example 1:
Input: low = 3, high = 3, zero = 1, one = 1
Output: 8
Explanation:
One possible valid good string is "011".
It can be constructed as follows: "" -> "0" -> "01" -> "011".
All binary strings from "000" to "111" are good strings in this example.
Example 2:
Input: low = 2, high = 3, zero = 1, one = 2
Output: 5
Explanation: The good strings are "00", "11", "000", "110", and "011".
Constraints:
1 <= low <= high <= 105
1 <= zero, one <= low
LeetCode
Count Ways To Build Good Strings - LeetCode
Can you solve this real interview question? Count Ways To Build Good Strings - Given the integers zero, one, low, and high, we can construct a string by starting with an empty string, and then at each step perform either of the following:
* Append the character…
* Append the character…
https://leetcode.com/problems/maximize-score-after-n-operations/
1799. Maximize Score After N Operations
Hard
601
57
Companies
You are given nums, an array of positive integers of size 2 * n. You must perform n operations on this array.
In the ith operation (1-indexed), you will:
Choose two elements, x and y.
Receive a score of i * gcd(x, y).
Remove x and y from nums.
Return the maximum score you can receive after performing n operations.
The function gcd(x, y) is the greatest common divisor of x and y.
Example 1:
Input: nums = [1,2]
Output: 1
Explanation: The optimal choice of operations is:
(1 * gcd(1, 2)) = 1
Example 2:
Input: nums = [3,4,6,8]
Output: 11
Explanation: The optimal choice of operations is:
(1 * gcd(3, 6)) + (2 * gcd(4, 8)) = 3 + 8 = 11
Example 3:
Input: nums = [1,2,3,4,5,6]
Output: 14
Explanation: The optimal choice of operations is:
(1 * gcd(1, 5)) + (2 * gcd(2, 4)) + (3 * gcd(3, 6)) = 1 + 4 + 9 = 14
Constraints:
1 <= n <= 7
nums.length == 2 * n
1 <= nums[i] <= 106
1799. Maximize Score After N Operations
Hard
601
57
Companies
You are given nums, an array of positive integers of size 2 * n. You must perform n operations on this array.
In the ith operation (1-indexed), you will:
Choose two elements, x and y.
Receive a score of i * gcd(x, y).
Remove x and y from nums.
Return the maximum score you can receive after performing n operations.
The function gcd(x, y) is the greatest common divisor of x and y.
Example 1:
Input: nums = [1,2]
Output: 1
Explanation: The optimal choice of operations is:
(1 * gcd(1, 2)) = 1
Example 2:
Input: nums = [3,4,6,8]
Output: 11
Explanation: The optimal choice of operations is:
(1 * gcd(3, 6)) + (2 * gcd(4, 8)) = 3 + 8 = 11
Example 3:
Input: nums = [1,2,3,4,5,6]
Output: 14
Explanation: The optimal choice of operations is:
(1 * gcd(1, 5)) + (2 * gcd(2, 4)) + (3 * gcd(3, 6)) = 1 + 4 + 9 = 14
Constraints:
1 <= n <= 7
nums.length == 2 * n
1 <= nums[i] <= 106
LeetCode
Maximize Score After N Operations - LeetCode
Can you solve this real interview question? Maximize Score After N Operations - You are given nums, an array of positive integers of size 2 * n. You must perform n operations on this array.
In the ith operation (1-indexed), you will:
* Choose two elements…
In the ith operation (1-indexed), you will:
* Choose two elements…
https://leetcode.com/problems/swapping-nodes-in-a-linked-list/
1721. Swapping Nodes in a Linked List
Medium
3.9K
131
Companies
You are given the head of a linked list, and an integer k.
Return the head of the linked list after swapping the values of the kth node from the beginning and the kth node from the end (the list is 1-indexed).
Example 1:
Input: head = [1,2,3,4,5], k = 2
Output: [1,4,3,2,5]
Example 2:
Input: head = [7,9,6,6,7,8,3,0,9,5], k = 5
Output: [7,9,6,6,8,7,3,0,9,5]
Constraints:
The number of nodes in the list is n.
1 <= k <= n <= 105
0 <= Node.val <= 100
1721. Swapping Nodes in a Linked List
Medium
3.9K
131
Companies
You are given the head of a linked list, and an integer k.
Return the head of the linked list after swapping the values of the kth node from the beginning and the kth node from the end (the list is 1-indexed).
Example 1:
Input: head = [1,2,3,4,5], k = 2
Output: [1,4,3,2,5]
Example 2:
Input: head = [7,9,6,6,7,8,3,0,9,5], k = 5
Output: [7,9,6,6,8,7,3,0,9,5]
Constraints:
The number of nodes in the list is n.
1 <= k <= n <= 105
0 <= Node.val <= 100
LeetCode
Swapping Nodes in a Linked List - LeetCode
Can you solve this real interview question? Swapping Nodes in a Linked List - You are given the head of a linked list, and an integer k.
Return the head of the linked list after swapping the values of the kth node from the beginning and the kth node from…
Return the head of the linked list after swapping the values of the kth node from the beginning and the kth node from…
https://leetcode.com/problems/swap-nodes-in-pairs/
24. Swap Nodes in Pairs
Medium
9.7K
369
Companies
Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)
Example 1:
Input: head = [1,2,3,4]
Output: [2,1,4,3]
Example 2:
Input: head = []
Output: []
Example 3:
Input: head = [1]
Output: [1]
Constraints:
The number of nodes in the list is in the range [0, 100].
0 <= Node.val <= 100
24. Swap Nodes in Pairs
Medium
9.7K
369
Companies
Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)
Example 1:
Input: head = [1,2,3,4]
Output: [2,1,4,3]
Example 2:
Input: head = []
Output: []
Example 3:
Input: head = [1]
Output: [1]
Constraints:
The number of nodes in the list is in the range [0, 100].
0 <= Node.val <= 100
LeetCode
Swap Nodes in Pairs - LeetCode
Can you solve this real interview question? Swap Nodes in Pairs - Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)…
https://leetcode.com/problems/maximum-twin-sum-of-a-linked-list/
2130. Maximum Twin Sum of a Linked List
Medium
1.8K
46
Companies
In a linked list of size n, where n is even, the ith node (0-indexed) of the linked list is known as the twin of the (n-1-i)th node, if 0 <= i <= (n / 2) - 1.
For example, if n = 4, then node 0 is the twin of node 3, and node 1 is the twin of node 2. These are the only nodes with twins for n = 4.
The twin sum is defined as the sum of a node and its twin.
Given the head of a linked list with even length, return the maximum twin sum of the linked list.
Example 1:
Input: head = [5,4,2,1]
Output: 6
Explanation:
Nodes 0 and 1 are the twins of nodes 3 and 2, respectively. All have twin sum = 6.
There are no other nodes with twins in the linked list.
Thus, the maximum twin sum of the linked list is 6.
Example 2:
Input: head = [4,2,2,3]
Output: 7
Explanation:
The nodes with twins present in this linked list are:
- Node 0 is the twin of node 3 having a twin sum of 4 + 3 = 7.
- Node 1 is the twin of node 2 having a twin sum of 2 + 2 = 4.
Thus, the maximum twin sum of the linked list is max(7, 4) = 7.
Example 3:
Input: head = [1,100000]
Output: 100001
Explanation:
There is only one node with a twin in the linked list having twin sum of 1 + 100000 = 100001.
Constraints:
The number of nodes in the list is an even integer in the range [2, 105].
1 <= Node.val <= 105
2130. Maximum Twin Sum of a Linked List
Medium
1.8K
46
Companies
In a linked list of size n, where n is even, the ith node (0-indexed) of the linked list is known as the twin of the (n-1-i)th node, if 0 <= i <= (n / 2) - 1.
For example, if n = 4, then node 0 is the twin of node 3, and node 1 is the twin of node 2. These are the only nodes with twins for n = 4.
The twin sum is defined as the sum of a node and its twin.
Given the head of a linked list with even length, return the maximum twin sum of the linked list.
Example 1:
Input: head = [5,4,2,1]
Output: 6
Explanation:
Nodes 0 and 1 are the twins of nodes 3 and 2, respectively. All have twin sum = 6.
There are no other nodes with twins in the linked list.
Thus, the maximum twin sum of the linked list is 6.
Example 2:
Input: head = [4,2,2,3]
Output: 7
Explanation:
The nodes with twins present in this linked list are:
- Node 0 is the twin of node 3 having a twin sum of 4 + 3 = 7.
- Node 1 is the twin of node 2 having a twin sum of 2 + 2 = 4.
Thus, the maximum twin sum of the linked list is max(7, 4) = 7.
Example 3:
Input: head = [1,100000]
Output: 100001
Explanation:
There is only one node with a twin in the linked list having twin sum of 1 + 100000 = 100001.
Constraints:
The number of nodes in the list is an even integer in the range [2, 105].
1 <= Node.val <= 105
LeetCode
Maximum Twin Sum of a Linked List - LeetCode
Can you solve this real interview question? Maximum Twin Sum of a Linked List - In a linked list of size n, where n is even, the ith node (0-indexed) of the linked list is known as the twin of the (n-1-i)th node, if 0 <= i <= (n / 2) - 1.
* For example…
* For example…
https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes/
1557. Minimum Number of Vertices to Reach All Nodes
Medium
Given a directed acyclic graph, with n vertices numbered from 0 to n-1, and an array edges where edges[i] = [fromi, toi] represents a directed edge from node fromi to node toi.
Find the smallest set of vertices from which all nodes in the graph are reachable. It's guaranteed that a unique solution exists.
Notice that you can return the vertices in any order.
Example 1:
Input: n = 6, edges = [[0,1],[0,2],[2,5],[3,4],[4,2]]
Output: [0,3]
Explanation: It's not possible to reach all the nodes from a single vertex. From 0 we can reach [0,1,2,5]. From 3 we can reach [3,4,2,5]. So we output [0,3].
Example 2:
Input: n = 5, edges = [[0,1],[2,1],[3,1],[1,4],[2,4]]
Output: [0,2,3]
Explanation: Notice that vertices 0, 3 and 2 are not reachable from any other node, so we must include them. Also any of these vertices can reach nodes 1 and 4.
Constraints:
2 <= n <= 10^5
1 <= edges.length <= min(10^5, n * (n - 1) / 2)
edges[i].length == 2
0 <= fromi, toi < n
All pairs (fromi, toi) are distinct.
1557. Minimum Number of Vertices to Reach All Nodes
Medium
Given a directed acyclic graph, with n vertices numbered from 0 to n-1, and an array edges where edges[i] = [fromi, toi] represents a directed edge from node fromi to node toi.
Find the smallest set of vertices from which all nodes in the graph are reachable. It's guaranteed that a unique solution exists.
Notice that you can return the vertices in any order.
Example 1:
Input: n = 6, edges = [[0,1],[0,2],[2,5],[3,4],[4,2]]
Output: [0,3]
Explanation: It's not possible to reach all the nodes from a single vertex. From 0 we can reach [0,1,2,5]. From 3 we can reach [3,4,2,5]. So we output [0,3].
Example 2:
Input: n = 5, edges = [[0,1],[2,1],[3,1],[1,4],[2,4]]
Output: [0,2,3]
Explanation: Notice that vertices 0, 3 and 2 are not reachable from any other node, so we must include them. Also any of these vertices can reach nodes 1 and 4.
Constraints:
2 <= n <= 10^5
1 <= edges.length <= min(10^5, n * (n - 1) / 2)
edges[i].length == 2
0 <= fromi, toi < n
All pairs (fromi, toi) are distinct.
LeetCode
Minimum Number of Vertices to Reach All Nodes - LeetCode
Can you solve this real interview question? Minimum Number of Vertices to Reach All Nodes - Given a directed acyclic graph, with n vertices numbered from 0 to n-1, and an array edges where edges[i] = [fromi, toi] represents a directed edge from node fromi to…
https://leetcode.com/problems/is-graph-bipartite/
785. Is Graph Bipartite?
Medium
6.5K
305
Companies
There is an undirected graph with n nodes, where each node is numbered between 0 and n - 1. You are given a 2D array graph, where graph[u] is an array of nodes that node u is adjacent to. More formally, for each v in graph[u], there is an undirected edge between node u and node v. The graph has the following properties:
There are no self-edges (graph[u] does not contain u).
There are no parallel edges (graph[u] does not contain duplicate values).
If v is in graph[u], then u is in graph[v] (the graph is undirected).
The graph may not be connected, meaning there may be two nodes u and v such that there is no path between them.
A graph is bipartite if the nodes can be partitioned into two independent sets A and B such that every edge in the graph connects a node in set A and a node in set B.
Return true if and only if it is bipartite.
Example 1:
Input: graph = [[1,2,3],[0,2],[0,1,3],[0,2]]
Output: false
Explanation: There is no way to partition the nodes into two independent sets such that every edge connects a node in one and a node in the other.
Example 2:
Input: graph = [[1,3],[0,2],[1,3],[0,2]]
Output: true
Explanation: We can partition the nodes into two sets: {0, 2} and {1, 3}.
Constraints:
graph.length == n
1 <= n <= 100
0 <= graph[u].length < n
0 <= graph[u][i] <= n - 1
graph[u] does not contain u.
All the values of graph[u] are unique.
If graph[u] contains v, then graph[v] contains u.
785. Is Graph Bipartite?
Medium
6.5K
305
Companies
There is an undirected graph with n nodes, where each node is numbered between 0 and n - 1. You are given a 2D array graph, where graph[u] is an array of nodes that node u is adjacent to. More formally, for each v in graph[u], there is an undirected edge between node u and node v. The graph has the following properties:
There are no self-edges (graph[u] does not contain u).
There are no parallel edges (graph[u] does not contain duplicate values).
If v is in graph[u], then u is in graph[v] (the graph is undirected).
The graph may not be connected, meaning there may be two nodes u and v such that there is no path between them.
A graph is bipartite if the nodes can be partitioned into two independent sets A and B such that every edge in the graph connects a node in set A and a node in set B.
Return true if and only if it is bipartite.
Example 1:
Input: graph = [[1,2,3],[0,2],[0,1,3],[0,2]]
Output: false
Explanation: There is no way to partition the nodes into two independent sets such that every edge connects a node in one and a node in the other.
Example 2:
Input: graph = [[1,3],[0,2],[1,3],[0,2]]
Output: true
Explanation: We can partition the nodes into two sets: {0, 2} and {1, 3}.
Constraints:
graph.length == n
1 <= n <= 100
0 <= graph[u].length < n
0 <= graph[u][i] <= n - 1
graph[u] does not contain u.
All the values of graph[u] are unique.
If graph[u] contains v, then graph[v] contains u.
LeetCode
Is Graph Bipartite? - LeetCode
Can you solve this real interview question? Is Graph Bipartite? - There is an undirected graph with n nodes, where each node is numbered between 0 and n - 1. You are given a 2D array graph, where graph[u] is an array of nodes that node u is adjacent to. More…
https://leetcode.com/problems/evaluate-division/
399. Evaluate Division
Medium
7.1K
634
Companies
You are given an array of variable pairs equations and an array of real numbers values, where equations[i] = [Ai, Bi] and values[i] represent the equation Ai / Bi = values[i]. Each Ai or Bi is a string that represents a single variable.
You are also given some queries, where queries[j] = [Cj, Dj] represents the jth query where you must find the answer for Cj / Dj = ?.
Return the answers to all queries. If a single answer cannot be determined, return -1.0.
Note: The input is always valid. You may assume that evaluating the queries will not result in division by zero and that there is no contradiction.
Example 1:
Input: equations = [["a","b"],["b","c"]], values = [2.0,3.0], queries = [["a","c"],["b","a"],["a","e"],["a","a"],["x","x"]]
Output: [6.00000,0.50000,-1.00000,1.00000,-1.00000]
Explanation:
Given: a / b = 2.0, b / c = 3.0
queries are: a / c = ?, b / a = ?, a / e = ?, a / a = ?, x / x = ?
return: [6.0, 0.5, -1.0, 1.0, -1.0 ]
Example 2:
Input: equations = [["a","b"],["b","c"],["bc","cd"]], values = [1.5,2.5,5.0], queries = [["a","c"],["c","b"],["bc","cd"],["cd","bc"]]
Output: [3.75000,0.40000,5.00000,0.20000]
Example 3:
Input: equations = [["a","b"]], values = [0.5], queries = [["a","b"],["b","a"],["a","c"],["x","y"]]
Output: [0.50000,2.00000,-1.00000,-1.00000]
Constraints:
1 <= equations.length <= 20
equations[i].length == 2
1 <= Ai.length, Bi.length <= 5
values.length == equations.length
0.0 < values[i] <= 20.0
1 <= queries.length <= 20
queries[i].length == 2
1 <= Cj.length, Dj.length <= 5
Ai, Bi, Cj, Dj consist of lower case English letters and digits.
399. Evaluate Division
Medium
7.1K
634
Companies
You are given an array of variable pairs equations and an array of real numbers values, where equations[i] = [Ai, Bi] and values[i] represent the equation Ai / Bi = values[i]. Each Ai or Bi is a string that represents a single variable.
You are also given some queries, where queries[j] = [Cj, Dj] represents the jth query where you must find the answer for Cj / Dj = ?.
Return the answers to all queries. If a single answer cannot be determined, return -1.0.
Note: The input is always valid. You may assume that evaluating the queries will not result in division by zero and that there is no contradiction.
Example 1:
Input: equations = [["a","b"],["b","c"]], values = [2.0,3.0], queries = [["a","c"],["b","a"],["a","e"],["a","a"],["x","x"]]
Output: [6.00000,0.50000,-1.00000,1.00000,-1.00000]
Explanation:
Given: a / b = 2.0, b / c = 3.0
queries are: a / c = ?, b / a = ?, a / e = ?, a / a = ?, x / x = ?
return: [6.0, 0.5, -1.0, 1.0, -1.0 ]
Example 2:
Input: equations = [["a","b"],["b","c"],["bc","cd"]], values = [1.5,2.5,5.0], queries = [["a","c"],["c","b"],["bc","cd"],["cd","bc"]]
Output: [3.75000,0.40000,5.00000,0.20000]
Example 3:
Input: equations = [["a","b"]], values = [0.5], queries = [["a","b"],["b","a"],["a","c"],["x","y"]]
Output: [0.50000,2.00000,-1.00000,-1.00000]
Constraints:
1 <= equations.length <= 20
equations[i].length == 2
1 <= Ai.length, Bi.length <= 5
values.length == equations.length
0.0 < values[i] <= 20.0
1 <= queries.length <= 20
queries[i].length == 2
1 <= Cj.length, Dj.length <= 5
Ai, Bi, Cj, Dj consist of lower case English letters and digits.
LeetCode
Evaluate Division - LeetCode
Can you solve this real interview question? Evaluate Division - You are given an array of variable pairs equations and an array of real numbers values, where equations[i] = [Ai, Bi] and values[i] represent the equation Ai / Bi = values[i]. Each Ai or Bi is…
https://leetcode.com/problems/shortest-bridge/
934. Shortest Bridge
Medium
3.7K
155
Companies
You are given an n x n binary matrix grid where 1 represents land and 0 represents water.
An island is a 4-directionally connected group of 1's not connected to any other 1's. There are exactly two islands in grid.
You may change 0's to 1's to connect the two islands to form one island.
Return the smallest number of 0's you must flip to connect the two islands.
Example 1:
Input: grid = [[0,1],[1,0]]
Output: 1
Example 2:
Input: grid = [[0,1,0],[0,0,0],[0,0,1]]
Output: 2
Example 3:
Input: grid = [[1,1,1,1,1],[1,0,0,0,1],[1,0,1,0,1],[1,0,0,0,1],[1,1,1,1,1]]
Output: 1
Constraints:
n == grid.length == grid[i].length
2 <= n <= 100
grid[i][j] is either 0 or 1.
There are exactly two islands in grid.
934. Shortest Bridge
Medium
3.7K
155
Companies
You are given an n x n binary matrix grid where 1 represents land and 0 represents water.
An island is a 4-directionally connected group of 1's not connected to any other 1's. There are exactly two islands in grid.
You may change 0's to 1's to connect the two islands to form one island.
Return the smallest number of 0's you must flip to connect the two islands.
Example 1:
Input: grid = [[0,1],[1,0]]
Output: 1
Example 2:
Input: grid = [[0,1,0],[0,0,0],[0,0,1]]
Output: 2
Example 3:
Input: grid = [[1,1,1,1,1],[1,0,0,0,1],[1,0,1,0,1],[1,0,0,0,1],[1,1,1,1,1]]
Output: 1
Constraints:
n == grid.length == grid[i].length
2 <= n <= 100
grid[i][j] is either 0 or 1.
There are exactly two islands in grid.
LeetCode
Shortest Bridge - LeetCode
Can you solve this real interview question? Shortest Bridge - You are given an n x n binary matrix grid where 1 represents land and 0 represents water.
An island is a 4-directionally connected group of 1's not connected to any other 1's. There are exactly…
An island is a 4-directionally connected group of 1's not connected to any other 1's. There are exactly…
https://leetcode.com/problems/top-k-frequent-elements/
347. Top K Frequent Elements
Medium
13.6K
497
Companies
Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.
Example 1:
Input: nums = [1,1,1,2,2,3], k = 2
Output: [1,2]
Example 2:
Input: nums = [1], k = 1
Output: [1]
Constraints:
1 <= nums.length <= 105
-104 <= nums[i] <= 104
k is in the range [1, the number of unique elements in the array].
It is guaranteed that the answer is unique.
Follow up: Your algorithm's time complexity must be better than O(n log n), where n is the array's size.
347. Top K Frequent Elements
Medium
13.6K
497
Companies
Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.
Example 1:
Input: nums = [1,1,1,2,2,3], k = 2
Output: [1,2]
Example 2:
Input: nums = [1], k = 1
Output: [1]
Constraints:
1 <= nums.length <= 105
-104 <= nums[i] <= 104
k is in the range [1, the number of unique elements in the array].
It is guaranteed that the answer is unique.
Follow up: Your algorithm's time complexity must be better than O(n log n), where n is the array's size.
LeetCode
Top K Frequent Elements - LeetCode
Can you solve this real interview question? Top K Frequent Elements - Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.
Example 1:
Input: nums = [1,1,1,2,2,3], k = 2
Output: [1…
Example 1:
Input: nums = [1,1,1,2,2,3], k = 2
Output: [1…
https://leetcode.com/problems/kth-largest-element-in-a-stream/
703. Kth Largest Element in a Stream
Easy
4.1K
2.5K
Companies
Design a class to find the kth largest element in a stream. Note that it is the kth largest element in the sorted order, not the kth distinct element.
Implement KthLargest class:
KthLargest(int k, int[] nums) Initializes the object with the integer k and the stream of integers nums.
int add(int val) Appends the integer val to the stream and returns the element representing the kth largest element in the stream.
Example 1:
Input
["KthLargest", "add", "add", "add", "add", "add"]
[[3, [4, 5, 8, 2]], [3], [5], [10], [9], [4]]
Output
[null, 4, 5, 5, 8, 8]
Explanation
KthLargest kthLargest = new KthLargest(3, [4, 5, 8, 2]);
kthLargest.add(3); // return 4
kthLargest.add(5); // return 5
kthLargest.add(10); // return 5
kthLargest.add(9); // return 8
kthLargest.add(4); // return 8
Constraints:
1 <= k <= 104
0 <= nums.length <= 104
-104 <= nums[i] <= 104
-104 <= val <= 104
At most 104 calls will be made to add.
It is guaranteed that there will be at least k elements in the array when you search for the kth element.
703. Kth Largest Element in a Stream
Easy
4.1K
2.5K
Companies
Design a class to find the kth largest element in a stream. Note that it is the kth largest element in the sorted order, not the kth distinct element.
Implement KthLargest class:
KthLargest(int k, int[] nums) Initializes the object with the integer k and the stream of integers nums.
int add(int val) Appends the integer val to the stream and returns the element representing the kth largest element in the stream.
Example 1:
Input
["KthLargest", "add", "add", "add", "add", "add"]
[[3, [4, 5, 8, 2]], [3], [5], [10], [9], [4]]
Output
[null, 4, 5, 5, 8, 8]
Explanation
KthLargest kthLargest = new KthLargest(3, [4, 5, 8, 2]);
kthLargest.add(3); // return 4
kthLargest.add(5); // return 5
kthLargest.add(10); // return 5
kthLargest.add(9); // return 8
kthLargest.add(4); // return 8
Constraints:
1 <= k <= 104
0 <= nums.length <= 104
-104 <= nums[i] <= 104
-104 <= val <= 104
At most 104 calls will be made to add.
It is guaranteed that there will be at least k elements in the array when you search for the kth element.
LeetCode
Kth Largest Element in a Stream - LeetCode
Can you solve this real interview question? Kth Largest Element in a Stream - You are part of a university admissions office and need to keep track of the kth highest test score from applicants in real-time. This helps to determine cut-off marks for interviews…
https://leetcode.com/problems/maximum-subsequence-score/
2542. Maximum Subsequence Score
Medium
637
31
Companies
You are given two 0-indexed integer arrays nums1 and nums2 of equal length n and a positive integer k. You must choose a subsequence of indices from nums1 of length k.
For chosen indices i0, i1, ..., ik - 1, your score is defined as:
The sum of the selected elements from nums1 multiplied with the minimum of the selected elements from nums2.
It can defined simply as: (nums1[i0] + nums1[i1] +...+ nums1[ik - 1]) * min(nums2[i0] , nums2[i1], ... ,nums2[ik - 1]).
Return the maximum possible score.
A subsequence of indices of an array is a set that can be derived from the set {0, 1, ..., n-1} by deleting some or no elements.
Example 1:
Input: nums1 = [1,3,3,2], nums2 = [2,1,3,4], k = 3
Output: 12
Explanation:
The four possible subsequence scores are:
- We choose the indices 0, 1, and 2 with score = (1+3+3) * min(2,1,3) = 7.
- We choose the indices 0, 1, and 3 with score = (1+3+2) * min(2,1,4) = 6.
- We choose the indices 0, 2, and 3 with score = (1+3+2) * min(2,3,4) = 12.
- We choose the indices 1, 2, and 3 with score = (3+3+2) * min(1,3,4) = 8.
Therefore, we return the max score, which is 12.
Example 2:
Input: nums1 = [4,2,3,1,1], nums2 = [7,5,10,9,6], k = 1
Output: 30
Explanation:
Choosing index 2 is optimal: nums1[2] * nums2[2] = 3 * 10 = 30 is the maximum possible score.
Constraints:
n == nums1.length == nums2.length
1 <= n <= 105
0 <= nums1[i], nums2[j] <= 105
1 <= k <= n
2542. Maximum Subsequence Score
Medium
637
31
Companies
You are given two 0-indexed integer arrays nums1 and nums2 of equal length n and a positive integer k. You must choose a subsequence of indices from nums1 of length k.
For chosen indices i0, i1, ..., ik - 1, your score is defined as:
The sum of the selected elements from nums1 multiplied with the minimum of the selected elements from nums2.
It can defined simply as: (nums1[i0] + nums1[i1] +...+ nums1[ik - 1]) * min(nums2[i0] , nums2[i1], ... ,nums2[ik - 1]).
Return the maximum possible score.
A subsequence of indices of an array is a set that can be derived from the set {0, 1, ..., n-1} by deleting some or no elements.
Example 1:
Input: nums1 = [1,3,3,2], nums2 = [2,1,3,4], k = 3
Output: 12
Explanation:
The four possible subsequence scores are:
- We choose the indices 0, 1, and 2 with score = (1+3+3) * min(2,1,3) = 7.
- We choose the indices 0, 1, and 3 with score = (1+3+2) * min(2,1,4) = 6.
- We choose the indices 0, 2, and 3 with score = (1+3+2) * min(2,3,4) = 12.
- We choose the indices 1, 2, and 3 with score = (3+3+2) * min(1,3,4) = 8.
Therefore, we return the max score, which is 12.
Example 2:
Input: nums1 = [4,2,3,1,1], nums2 = [7,5,10,9,6], k = 1
Output: 30
Explanation:
Choosing index 2 is optimal: nums1[2] * nums2[2] = 3 * 10 = 30 is the maximum possible score.
Constraints:
n == nums1.length == nums2.length
1 <= n <= 105
0 <= nums1[i], nums2[j] <= 105
1 <= k <= n
LeetCode
Maximum Subsequence Score - LeetCode
Can you solve this real interview question? Maximum Subsequence Score - You are given two 0-indexed integer arrays nums1 and nums2 of equal length n and a positive integer k. You must choose a subsequence of indices from nums1 of length k.
For chosen indices…
For chosen indices…
https://leetcode.com/problems/new-21-game/
837. New 21 Game
Medium
1.2K
817
Companies
Alice plays the following game, loosely based on the card game "21".
Alice starts with 0 points and draws numbers while she has less than k points. During each draw, she gains an integer number of points randomly from the range [1, maxPts], where maxPts is an integer. Each draw is independent and the outcomes have equal probabilities.
Alice stops drawing numbers when she gets k or more points.
Return the probability that Alice has n or fewer points.
Answers within 10-5 of the actual answer are considered accepted.
Example 1:
Input: n = 10, k = 1, maxPts = 10
Output: 1.00000
Explanation: Alice gets a single card, then stops.
Example 2:
Input: n = 6, k = 1, maxPts = 10
Output: 0.60000
Explanation: Alice gets a single card, then stops.
In 6 out of 10 possibilities, she is at or below 6 points.
Example 3:
Input: n = 21, k = 17, maxPts = 10
Output: 0.73278
Constraints:
0 <= k <= n <= 104
1 <= maxPts <= 104
837. New 21 Game
Medium
1.2K
817
Companies
Alice plays the following game, loosely based on the card game "21".
Alice starts with 0 points and draws numbers while she has less than k points. During each draw, she gains an integer number of points randomly from the range [1, maxPts], where maxPts is an integer. Each draw is independent and the outcomes have equal probabilities.
Alice stops drawing numbers when she gets k or more points.
Return the probability that Alice has n or fewer points.
Answers within 10-5 of the actual answer are considered accepted.
Example 1:
Input: n = 10, k = 1, maxPts = 10
Output: 1.00000
Explanation: Alice gets a single card, then stops.
Example 2:
Input: n = 6, k = 1, maxPts = 10
Output: 0.60000
Explanation: Alice gets a single card, then stops.
In 6 out of 10 possibilities, she is at or below 6 points.
Example 3:
Input: n = 21, k = 17, maxPts = 10
Output: 0.73278
Constraints:
0 <= k <= n <= 104
1 <= maxPts <= 104
LeetCode
New 21 Game - LeetCode
Can you solve this real interview question? New 21 Game - Alice plays the following game, loosely based on the card game "21".
Alice starts with 0 points and draws numbers while she has less than k points. During each draw, she gains an integer number of…
Alice starts with 0 points and draws numbers while she has less than k points. During each draw, she gains an integer number of…