小榕流光的专栏

题目链接：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

题目链接：https://leetcode.com/problems/minimum-height-trees/ For a undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all po

题目链接：https://leetcode.com/problems/course-schedule/ 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 course

题目链接: 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