Is It A Tree? Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 6961    Accepted Submission(s): 1619 [题目链接]http://acm.hdu.edu.cn/showproblem.php?pid=1325 这题如果用并查集做的话,最后判断的时候还是要看一个结点的入度是否为大于1(纯并查集的…

Description A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edges between nodes satisfying the following properties. There is exactly one node, called the root, t…

HDU认为1>2,3>2不是树,POJ认为是,而Virtual Judge上引用的是POJ数据这就是唯一的区别....(因为这个瞎折腾了半天) 此题因为是为了熟悉并查集而刷,其实想了下其实好好利用sort应该能更简单A掉,下次有空再去试试... 题目大意:判断是否为树,so: 1,无环: 2,除了根,所有的入度为1,根入度为0: 3,这个结构只有一个根,不然是森林了:4.空树也是树,即第一次输入的两个数字为0 0则是树,其他时候输入只是结束条件 因为POJ和HDU题面一样,要求不一样,所以这题…

POJ题目网址:http://poj.org/problem?id=1308 HDU题目网址:http://acm.hdu.edu.cn/showproblem.php?pid=1272 并查集的运用,如果想要形成一棵树,那么我们应该只能有一个根,并查集联合次数为节点数-1. //Asimple //#include <bits/stdc++.h> #include <iostream> #include <sstream> #include <algorithm…

Wooden Sticks Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 8899    Accepted Submission(s): 3630 [解题思路]初学贪心仅知道一些理论的知识,这题说是贪心自己也没啥感觉,做题的思路是在抛开贪心的概念然后按照自己的想法实现出来,实现之后想在思路中找到贪心的影子,只能看到每次都是找尽可能多的s…

Is It A Tree? Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 24237   Accepted: 8311 Description A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edge…

Is It A Tree? 题目链接: http://acm.hust.edu.cn/vjudge/contest/123393#problem/M Description A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edges between nodes satisfy…

Is It A Tree? Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 18778   Accepted: 6395 Description A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edge…

Is It A Tree? Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 31092   Accepted: 10549 Description A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edg…

Is It A Tree? Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 32052   Accepted: 10876 Description A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edg…