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.