摘要：Given a string which contains only lowercase letters, remove duplicate letters so that every letter appear once and only once. You must make sure your 阅读全文

摘要：Given a collection of intervals, find the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping. Note: Exam 阅读全文

摘要：There are a number of spherical balloons spread in two-dimensional space. For each balloon, provided input is the start and end coordinates of the hor 阅读全文

摘要：Assume you are an awesome parent and want to give your children some cookies. But, you should give each child at most one cookie. Each child i has a g 阅读全文

摘要：Given an array of non-negative integers, you are initially positioned at the first index of the array. Each element in the array represents your maxim 阅读全文

摘要：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 re 阅读全文

摘要：There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it cost 阅读全文