Robina Li

You are given a 2D array of integers envelopes where envelopes[i] = [wi, hi] represents the width and the height of an envelope.

You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed. All houses at this place are arranged in a...

Design your implementation of the circular queue. The circular queue is a linear data structure in which the operations are performed based on FIFO (First In First Out) principle and...

Given a list of folders folder, return the folders after removing all sub-folders in those folders. You may return the answer in any order.

You are given a 2D integer array orders, where orders[i] = [price_i, amount_i, orderType_i] denotes that amount_i orders have been placed of type orderType_i at price price_i. The orderType_i is:...

You are given an m x n integer array grid. There is a robot initially located at the top-left corner (i.e., grid[0][0]). The robot tries to move to the bottom-right...

Given an m x n matrix mat, return an array of all the elements of the matrix in a diagonal order.

Given an integer array nums, rotate the array to the right by k steps, where k is non-negative.

This page collects ready-to-use C++ templates for every major binary search pattern you’ll encounter on LeetCode — from basic sorted-array lookup to rotated arrays, 2D matrices, and “search on the...

Given an integer array nums and two integers lower and upper, return the number of range sums that lie in [lower, upper] inclusive.