HDU 1829

A Bug's Life

Time Limit: 15000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 11768    Accepted Submission(s): 3827

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!

这道题涉及并查集问题，但是不同于一般的并查集，这里要扩展成2倍的并查集空间，以便在合并处理时能判断冲突问题。其他的就是一般的查找和合并，要注意的是输入直接用scanf("%d",&t)，否则会出现WA.

#include<iostream>#include<cstdio>#include<climits>#include<memory.h>using namespace std;const int MAX = 2000;int a[4010];bool ok;void init(int n){    int i;    for(i=1;i<=MAX+n;++i)a[i] = i;    ok = true;}int check(int x){    if(x!=a[x]){        a[x] = check(a[x]);    }    return a[x];}void exam(int x,int y){    int fx,fy;    fx = check(x);    fy = check(y-MAX);    if(fx==fy){        ok = false;        return;    }    fy = check(y);    if(fx!=fy){        a[fx] = a[fy];    }}int main(){    int t,i,n,m,x,y,k;    scanf("%d",&t);    for(i=1;i<=t;++i){        scanf("%d %d",&n,&m);        init(n);        for(k=1;k<=m;++k){            scanf("%d %d",&x,&y);            if(ok){                exam(x,y+MAX);                exam(y,x+MAX);            }        }        printf("Scenario #%d:\n",i);        if(ok){            printf("No suspicious bugs found!\n");        }else{            printf("Suspicious bugs found!\n");        }        printf("\n");    }    return 0;}