2021-12-11
878. Nth Magical Number
Topic: Math, Binary Search
Difficulty: Hard
Problem:
A positive integer is magical if it is divisible by either
Given the three integers
Example 1:
Example 2:
Example 3:
Example 4:
Constraints:
878. Nth Magical Number
Topic: Math, Binary Search
Difficulty: Hard
Problem:
A positive integer is magical if it is divisible by either
a or b.Given the three integers
n, a, and b, return the n^th magical number. Since the answer may be very large, return it modulo 10^9 + 7.Example 1:
Input: n = 1, a = 2, b = 3
Output: 2
Example 2:
Input: n = 4, a = 2, b = 3
Output: 6
Example 3:
Input: n = 5, a = 2, b = 4
Output: 10
Example 4:
Input: n = 3, a = 6, b = 4
Output: 8
Constraints:
1 <= n <= 10^92 <= a, b <= 4 * 10^42021-12-12
416. Partition Equal Subset Sum
Topic: Array, Dynamic Programming
Difficulty: Medium
Problem:
Given a non-empty array
Example 1:
Example 2:
Constraints:
•
•
416. Partition Equal Subset Sum
Topic: Array, Dynamic Programming
Difficulty: Medium
Problem:
Given a non-empty array
nums containing only positive integers, find if the array can be partitioned into two subsets such that the sum of elements in both subsets is equal.Example 1:
Input: nums = [1,5,11,5]
Output: true
Explanation: The array can be partitioned as [1, 5, 5] and [11].
Example 2:
Input: nums = [1,2,3,5]
Output: false
Explanation: The array cannot be partitioned into equal sum subsets.
Constraints:
•
1 <= nums.length <= 200•
1 <= nums[i] <= 1002021-12-13
1446. Consecutive Characters
Topic: String
Difficulty: Easy
Problem:
The power of the string is the maximum length of a non-empty substring that contains only one unique character.
Given a string
Example 1:
Example 2:
Example 3:
Example 4:
Example 5:
Constraints:
•
•
1446. Consecutive Characters
Topic: String
Difficulty: Easy
Problem:
The power of the string is the maximum length of a non-empty substring that contains only one unique character.
Given a string
s, return the power of s.Example 1:
Input: s = "leetcode"
Output: 2
Explanation: The substring "ee" is of length 2 with the character 'e' only.
Example 2:
Input: s = "abbcccddddeeeeedcba"
Output: 5
Explanation: The substring "eeeee" is of length 5 with the character 'e' only.
Example 3:
Input: s = "triplepillooooow"
Output: 5
Example 4:
Input: s = "hooraaaaaaaaaaay"
Output: 11
Example 5:
Input: s = "tourist"
Output: 1
Constraints:
•
1 <= s.length <= 500•
s consists of only lowercase English letters.2021-12-14
938. Range Sum of BST
Topic: Tree, Depth-First Search, Binary Search Tree, Binary Tree
Difficulty: Easy
Problem:
Given the
Example 1:
Image: https://assets.leetcode.com/uploads/2020/11/05/bst1.jpg
Example 2:
Image: https://assets.leetcode.com/uploads/2020/11/05/bst2.jpg
Constraints:
• The number of nodes in the tree is in the range
•
•
• All
938. Range Sum of BST
Topic: Tree, Depth-First Search, Binary Search Tree, Binary Tree
Difficulty: Easy
Problem:
Given the
root node of a binary search tree and two integers low and high, return the sum of values of all nodes with a value in the inclusive range [low, high].Example 1:
Image: https://assets.leetcode.com/uploads/2020/11/05/bst1.jpg
Input: root = [10,5,15,3,7,null,18], low = 7, high = 15
Output: 32
Explanation: Nodes 7, 10, and 15 are in the range [7, 15]. 7 + 10 + 15 = 32.
Example 2:
Image: https://assets.leetcode.com/uploads/2020/11/05/bst2.jpg
Input: root = [10,5,15,3,7,13,18,1,null,6], low = 6, high = 10
Output: 23
Explanation: Nodes 6, 7, and 10 are in the range [6, 10]. 6 + 7 + 10 = 23.
Constraints:
• The number of nodes in the tree is in the range
[1, 2 * 10^4].•
1 <= Node.val <= 10^5•
1 <= low <= high <= 10^5• All
Node.val are unique.2021-12-15
147. Insertion Sort List
Topic: Linked List, Sorting
Difficulty: Medium
Problem:
Given the
The steps of the insertion sort algorithm:
1. Insertion sort iterates, consuming one input element each repetition and growing a sorted output list.
2. At each iteration, insertion sort removes one element from the input data, finds the location it belongs within the sorted list and inserts it there.
3. It repeats until no input elements remain.
The following is a graphical example of the insertion sort algorithm. The partially sorted list (black) initially contains only the first element in the list. One element (red) is removed from the input data and inserted in-place into the sorted list with each iteration.
Image: https://upload.wikimedia.org/wikipedia/commons/0/0f/Insertion-sort-example-300px.gif
Example 1:
Image: https://assets.leetcode.com/uploads/2021/03/04/sort1linked-list.jpg
Example 2:
Image: https://assets.leetcode.com/uploads/2021/03/04/sort2linked-list.jpg
Constraints:
• The number of nodes in the list is in the range
•
147. Insertion Sort List
Topic: Linked List, Sorting
Difficulty: Medium
Problem:
Given the
head of a singly linked list, sort the list using insertion sort, and return the sorted list's head.The steps of the insertion sort algorithm:
1. Insertion sort iterates, consuming one input element each repetition and growing a sorted output list.
2. At each iteration, insertion sort removes one element from the input data, finds the location it belongs within the sorted list and inserts it there.
3. It repeats until no input elements remain.
The following is a graphical example of the insertion sort algorithm. The partially sorted list (black) initially contains only the first element in the list. One element (red) is removed from the input data and inserted in-place into the sorted list with each iteration.
Image: https://upload.wikimedia.org/wikipedia/commons/0/0f/Insertion-sort-example-300px.gif
Example 1:
Image: https://assets.leetcode.com/uploads/2021/03/04/sort1linked-list.jpg
Input: head = [4,2,1,3]
Output: [1,2,3,4]
Example 2:
Image: https://assets.leetcode.com/uploads/2021/03/04/sort2linked-list.jpg
Input: head = [-1,5,3,4,0]
Output: [-1,0,3,4,5]
Constraints:
• The number of nodes in the list is in the range
[1, 5000].•
-5000 <= Node.val <= 5000