Robina Li

Given an m x n integer matrix, if an element is 0, set its entire row and column to 0. You must do it in place.

Given n nodes labeled 0 to n-1 and a list of undirected edges, determine if these edges form a valid tree.

Given an integer array nums where exactly two elements appear once and all other elements appear exactly twice, find the two elements that appear only once. Return them in any...

You are given n train rides with distances dist[i]. Each train departs at an integer hour, so you must wait until the next whole hour to board the next train...

Implement a thread-safe bounded blocking queue with the following methods: BoundedBlockingQueue(int capacity) – initialize with max capacity void enqueue(int element) – add element to the back; blocks if the queue...

Two different threads will call foo and bar respectively. Design a mechanism so that "foobar" is printed n times by alternating between the two threads: foo always prints first, then...

Given an input string s, reverse the order of the words. A word is a sequence of non-space characters. Words are separated by at least one space. Return a string...

You are given two strings s and t. String t is generated by randomly shuffling s and then adding one more letter at a random position. Return the letter that...

Given two strings word1 and word2, merge them by adding letters in alternating order, starting with word1. If one string is longer, append the remaining letters at the end.

Given a string s representing a list of words, where each letter can be replaced by a group of letters inside braces {a,b,c}, return all possible words in sorted order....