Robina Li

Design a queue that supports push and pop operations in the front, middle, and back.

Given an m x n grid of characters board and a string word, return true if word exists in the grid.

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

The n-queens puzzle is the problem of placing n queens on an n x n chessboard such that no two queens attack each other.

Given two strings s and t, return true if they are equal when both are typed into empty text editors. '#' means a backspace character.

Given a list of accounts where each element accounts[i] is a list of strings, where the first element accounts[i][0] is a name, and the rest of the elements are emails...

Given a m x n grid filled with non-negative numbers, find a path from top-left to bottom-right, which minimizes the sum of all numbers along its path.

Given an array of integers arr and an integer d. In one step you can jump from index i to index:

Given an integer array nums, return the number of longest increasing subsequences.

Given an array of strings words and an integer k, return the k most frequent strings.