[LeetCode] 814. Binary Tree Pruning
Given the root of a binary tree, return the same tree where every subtree (of the given tree) not containing a 1 has been removed. A subtree of a node node is node plus every node that is a descendant
[LeetCode] 1010. Pairs of Songs With Total Durations Divisible by 60
You are given a list of songs where the ith song has a duration of time[i] seconds. Return the number of pairs of songs for which their total duration in seconds is divisible by 60. Formally, we want
[LeetCode] 395. Longest Substring with At Least K Repeating Characters
Given a string s and an integer k, return the length of the longest substring of s such that the frequency of each character in this substring is greater than or equal to k. if no such substring exist
[LeetCode] 1404. Number of Steps to Reduce a Number in Binary Representation to One
Given the binary representation of an integer as a string s, return the number of steps to reduce it to 1 under the following rules:If the current number is even, you have to divide it by 2.If the cur
[LeetCode] 1582. Special Positions in a Binary Matrix
Given an m x n binary matrix mat, return the number of special positions in mat. A position (i, j) is called special if mat[i][j] == 1 and all other elements in row i and column j are 0 (row
[LeetCode] 1283. Find the Smallest Divisor Given a Threshold
Given an array of integers nums and an integer threshold, we will choose a positive integer divisor, divide all the array by it, and sum the division’s result. Find the smallest divisor such that the
[LeetCode] 135. Candy
There are N children standing in a line. Each child is assigned a rating value. You are giving candies to these children subjected to the following requirements: Each child must have at least one cand
[LeetCode] 1219. Path with Maximum Gold
In a gold mine grid of size m * n, each cell in this mine has an integer representing the amount of gold in that cell, 0 if it is empty. Return the maximum amount of gold you can collect under the con