摘要:
参考百度百科:Trie树 a trie, also called digital tree and sometimes radix tree or prefix tree (as they can be searched by prefixes) The time complexity to ins 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 t 阅读全文
摘要:
The hint provided by leetcode is: Hints: BFS: 典型的拓扑排序。原理也很简单,在一个有向图中,每次找到一个没有前驱节点的节点(也就是入度为0的节点),然后把它指向其他节点的边都去掉,重复这个过程(BFS),直到所有节点已被找到,或者没有符合条件的节点(如果 阅读全文