James Pan

原题网址：https://leetcode.com/problems/course-schedule-ii/There are a total of n courses you have to take, labeled from 0 to n - 1.Some courses may have prerequisites, for example to take cour

原题网址：https://leetcode.com/problems/alien-dictionary/There is a new alien language which uses the latin alphabet. However, the order among letters are unknown to you. You receive a list of words