Pyramid Transition Matrix You are stacking blocks to form a pyramid. Each block has a color, which is represented by a single letter. Each row of blocks contains one less block than the row benea...

Count Negative Numbers in a Sorted Matrix Given a m x n matrix grid which is sorted in non-increasing order both row-wise and column-wise, return the number of negative numbers in grid.   Examp...

Minimum Penalty for a Shop You are given the customer visit log of a shop represented by a 0-indexed string customers consisting only of characters ‘N’ and ‘Y’: if the ith character is 'Y', it m...

Maximize Happiness of Selected Children You are given an array happiness of length n, and a positive integer k. There are n children standing in a queue, where the ith child has happiness value ...

Apple Redistribution into Boxes You are given an array apple of size n and an array capacity of size m. There are n packs where the ith pack contains apple[i] apples. There are m boxes as well, ...

Two Best Non-Overlapping Events You are given a 0-indexed 2D integer array of events where events[i] = [startTimei, endTimei, valuei]. The ith event starts at startTimei and ends at endTimei, and...

Delete Columns to Make Sorted III You are given an array of n strings strs, all of the same length. We may choose any deletion indices, and we delete all the characters in those indices for each...

Delete Columns to Make Sorted II You are given an array of n strings strs, all of the same length. We may choose any deletion indices, and we delete all the characters in those indices for each ...

Find All People With Secret You are given an integer n indicating there are n people numbered from 0 to n - 1. You are also given a 0-indexed 2D integer array meetings where meetings[i] = [xi, yi...

Delete Columns to Make Sorted You are given an array of n strings strs, all of the same length. The strings can be arranged such that there is one on each line, making a grid. For example, strs...