hdu-3314-并查集

来源：互联网发布：验证码滑动加速算法编辑：程序博客网时间：2024/05/16 05:09

http://acm.hdu.edu.cn/showproblem.php?pid=3314

如果形成环，则标记一下，最后统计一遍每个人得多少票，看是否唯一即可

#include <cstdio>#include <cmath>#include <cstring>#include <string>#include <algorithm>#include <queue>#include <map>#include <set>#include <vector>#include <iostream>using namespace std;const double pi=acos(-1.0);double eps=0.000001;int fa[123456];int find(int x){    if (fa[x]==x)        return x;    else return fa[x]=find(fa[x]);}int num[123456];int main(){    int n,m;    while(scanf("%d",&n)!=EOF)    {        set<int > del;        del.clear();        for (int i=0; i<n; i++) fa[i]=i ,num[i]=0;        for (int i=0; i<n; i++)        {            int x;            scanf("%d",&x);            int fx=find(x);            int fy=find(i);            if (x==i) continue;            if (fx!=fy)                fa[fy]=x;            else                del.insert(fx);        }        int maxx=0;        int maxi=-1;        for (int i=0; i<n; i++)        {            int fx=find(i);            if (del.find(fx)!=del.end())       //找到                continue;            else                num[fx]++;        }        for (int i=0; i<n; i++)        {            if (num[i]>maxx)   maxx=num[i],maxi=i;        }        int cun=0;        for (int i=0; i<n; i++)            if (num[i]==maxx) cun++;        if (cun==1)            printf("%d\n",maxi);        else            printf("Trouble\n");    }    return 0;}

0 0