hdu1829 A Bug's Life --分组并查集

原题链接： http://acm.hdu.edu.cn/showproblem.php?pid=1829

一：原题内容

Problem Description

Background
Professor Hopper is researching the sexual behavior of a rare species of bugs. He assumes that they feature two different genders and that they only interact with bugs of the opposite gender. In his experiment, individual bugs and their interactions were easy to identify, because numbers were printed on their backs.

Problem
Given a list of bug interactions, decide whether the experiment supports his assumption of two genders with no homosexual bugs or if it contains some bug interactions that falsify it.

 

Input

The first line of the input contains the number of scenarios. Each scenario starts with one line giving the number of bugs (at least one, and up to 2000) and the number of interactions (up to 1000000) separated by a single space. In the following lines, each interaction is given in the form of two distinct bug numbers separated by a single space. Bugs are numbered consecutively starting from one.

Output

The output for every scenario is a line containing "Scenario #i:", where i is the number of the scenario starting at 1, followed by one line saying either "No suspicious bugs found!" if the experiment is consistent with his assumption about the bugs' sexual behavior, or "Suspicious bugs found!" if Professor Hopper's assumption is definitely wrong.

Sample Input

23 31 22 31 34 21 23 4

 

Sample Output

Scenario #1:Suspicious bugs found!Scenario #2:No suspicious bugs found!
Hint
Huge input,scanf is recommended.

二：分析理解

教授正在探求一种小虫是不是异性交配，没有同性交配。

n个小虫，分为雌雄，编号从1到n，现给定m对关系a，b，表示编号a和b可以交配（异性），问是否会出现矛盾？也就是下例：

1 2

2 3

1 3

出现矛盾，2与3是同性交配了。

三：AC代码

#include<iostream>    #include<string.h>  #include<algorithm>  using namespace std;int pre[2015];int sex[2015];bool flag;int T;int n, m;int a, b;int FindRoot(int x){if (x != pre[x])pre[x] = FindRoot(pre[x]);return pre[x];}void Union(int x, int y){int x_root = FindRoot(x);int y_root = FindRoot(y);if (x_root != y_root)pre[x_root] = y_root;}int main(){scanf("%d", &T);for (int cas = 1; cas <= T; cas++){scanf("%d%d", &n, &m);memset(sex, 0, sizeof(sex));for (int i = 1; i < 2005; i++)pre[i] = i;flag = 0;while (m--){scanf("%d%d", &a, &b);if (flag) continue;//教授的假设已经失败，无需再做if (FindRoot(a) == FindRoot(b)) { flag = 1; continue; }if (sex[a] == 0)sex[a] = b;elseUnion(sex[a], b);if (sex[b] == 0)sex[b] = a;elseUnion(sex[b], a);}printf("Scenario #%d:\n", cas);if (flag)printf("Suspicious bugs found!\n");elseprintf("No suspicious bugs found!\n");printf("\n");}return 0;}