[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] 378. Kth Smallest Element in a Sorted Matrix
Given an n x n matrix where each of the rows and columns is sorted in ascending order, return the kth smallest element in the matrix. Note that it is the kth smallest element in the sorted order, not
[LeetCode] 733. Flood Fill
You are given an image represented by an m x n grid of integers image, where image[i][j] represents the pixel value of the image. You are also given three integers sr, sc, and color. Your task is to p
[LeetCode] 695. Max Area of Island
You are given an m x n binary matrix grid. An island is a group of 1’s (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded
[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