并查集 水题

题目链接

#include <iostream>#include<stdio.h>#include<math.h>#include<algorithm>#include<string.h>#include<stack>#include<queue>#include<vector>#include<stdlib.h>using namespace std;const int INF =2100000000;int pre[1010];void Init(int n){    for(int i=0;i<=n;i++)        pre[i]=i;}int finds(int x){    return pre[x]==x?x:pre[x]=finds(pre[x]);}void jion(int x,int y){    int fx=finds(x);    int fy=finds(y);    pre[fy]=fx;}int main(){    int n_case;    scanf("%d",&n_case);    while(n_case--)    {        int people,contect,i;        scanf("%d %d",&people,&contect);        Init(people);        for(i=1;i<=contect;i++)        {            int x,y;            scanf("%d%d",&x,&y);            jion(x,y);        }        int ans=0;        for(i=1;i<=people;i++)        {            if(pre[i]==i) ans++;        }        printf("%d\n",ans);    }    return 0;}