HDU - 3018 Ant Country consist of N towns.There are M roads connecting the towns. Ant Tony,together with his friends,wants to go through every part of the country. They intend to visit every road , and every road must be visited for exact one time.Ho…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=3018 Ant Trip Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1658    Accepted Submission(s): 641 Problem Description Ant Country consist of N to…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3018 题目大意:有n个点,m条边,人们希望走完所有的路,且每条道路只能走一遍.至少要将人们分成几组. 解题思路:先用并查集求出所有的连通块,然后判断每个连通块内点的度数,如果有奇数点则需要的组数ans+=奇数点/2:反之,所需组数ans+=1.注意:如果遇到孤立点即度数为0的点则不用算进去,因为没有跟他相连的边. 代码: #include<iostream> #include<cstdio&…

Ant Trip Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 904    Accepted Submission(s): 338 Problem Description Ant Country consist of N towns.There are M roads connecting the towns. Ant Tony,to…

Ant Trip Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3660    Accepted Submission(s): 1455 Problem Description Ant Country consist of N towns.There are M roads connecting the towns. Ant Tony,…

Ant Trip Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description Ant Country consist of N towns.There are M roads connecting the towns. Ant Tony,together with his friends,wants to go through every part…

http://acm.hdu.edu.cn/showproblem.php?pid=1116 给你一些英文单词,判断所有单词能不能连成一串,类似成语接龙的意思.但是如果有多个重复的单词时,也必须满足这样的条件才能算YES.否则都是不可能的情况. 欧拉回路和欧拉通路的判定可以总结为如下: 1)所有的点联通 2)欧拉回路中所有点的入度和出度一样. 3)欧拉通路中起点的入度 - 出度 = 1,终点的 初度 - 入度 = 1, 其他的所有点入度 = 出度: 所以用并查集搞就好了 #pragma comm…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1878 题目大意:欧拉回路是指不令笔离开纸面,可画过图中每条边仅一次,且可以回到起点的一条回路.现给定一个图,问是否存在欧拉回路? 解题思路:判断无向图是否存在欧拉回路,判断每个点的度数是否为偶数+并查集确认连通性. 代码: #include<iostream> #include<cstring> #include<cstdio> #define CLR(arr,val) m…

并查集水题. 一个图存在欧拉回路的判断条件: 无向图存在欧拉回路的充要条件 一个无向图存在欧拉回路,当且仅当该图所有顶点度数都是偶数且该图是连通图. 有向图存在欧拉回路的充要条件 一个有向图存在欧拉回路,所有顶点的入度等于出度且该图是连通图 1.每次加点都对两个点的度数加1 2.加点时如果两点不在同一集合,则合并两点所在集合. 3.最后统计每个点度数是否为偶数,并且判断连不连通. 代码: #include <iostream> #include <cstdio> #include…

解题报告:题目大意,给出一个无向图,判断图中是否存在欧拉回路. 判断一个无向图中是否有欧拉回路有一个充要条件,就是这个图中不存在奇度定点,然后还要判断的就是连通分支数是否为1,即这个图是不是连通的,这个用并查集就可以了. #include<cstdio> #include<cstring> #include<iostream> using namespace std; ]; ]; int find(int n) { return prim[n]==n? n:(prim[…