摘要：https://leetcode.com/problems/minimum-height-trees/discuss/76055/Share-some-thoughts For a undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a... 阅读全文

摘要：Check whether the original sequence org can be uniquely reconstructed from the sequences in seqs. The org sequence is a permutation of the integers from 1 to n, with 1 ≤ n ≤ 104. Reconstruction means... 阅读全文

摘要：bfs indegree Pretty much the same as the course schedule 1 The only diff is to return the order of the classes, which we can use a list as a container 阅读全文

摘要：Use bfs The given is [[1,0]] To take course 1 you should have finished course 0. So it is possible. So we need to convert the input into something lik 阅读全文

摘要：Using “break” in for loop public class Test { public static void main(String args[]) { int [] numbers = {10, 20, 30, 40, 50}; for(int x : numbers ) { 阅读全文

摘要：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 0 you have to 阅读全文

摘要：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 0 you have to 阅读全文