[LeetCode] 18. 4Sum
Given an array nums of n integers, return an array of all the unique quadruplets [nums[a], nums[b], nums[c], nums[d]] such that:0 <= a, b, c, d < na, b, c, and d are distinct.nums[a] + nums
[LeetCode] 80. Remove Duplicates from Sorted Array II
Given an integer array nums sorted in non-decreasing order, remove some duplicates in-place such that each unique element appears at most twice. The relative order of the elements should be kept the s
[LeetCode] 1248. Count Number of Nice Subarrays
Given an array of integers nums and an integer k. A continuous subarray is called nice if there are k odd numbers on it. Return the number of nice sub-arrays. Example 1:Input: nums = [1,1,2,1,1],
[LeetCode] 36. Valid Sudoku
Determine if a 9 x 9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:Each row must contain the digits 1-9 without repetition.Each column must contain
[LeetCode] 994. Rotting Oranges
You are given an m x n grid where each cell can have one of three values:0 representing an empty cell,1 representing a fresh orange, or2 representing a rotten orange.Every minute, any fresh orange tha
[LeetCode] 78. Subsets
Given an integer array nums of unique elements, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Return the solution in any order. Example 1:Input: num
[LeetCode] 523. Continuous Subarray Sum
Given an integer array nums and an integer k, return true if nums has a good subarray or false otherwise. A good subarray is a subarray where:its length is at least two, andthe sum of the elements of
[LeetCode] 560. Subarray Sum Equals K
Given an array of integers nums and an integer k, return the total number of subarrays whose sum equals to k. A subarray is a contiguous non-empty sequence of elements within an array. Example 1:Input