HDU 1213 How Many Tables

HDU 1213 How Many Tables

考察基础的并查集。

#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<string.h>
#include<string>
#include<math.h>
using namespace std;
int m,n;
int per[1005];
void init()//初始化；
{
    for(int i = 0; i <= n; i ++)
    {
        per[i] = i;
    }
}
int find(int x)//寻找根节点；
{
    int i = x,j,k;
    while(per[i] != i)
    {
        i = per[i];
    }
    return i;
}
void join(int x,int y)//合并；
{
    int s = find(x);
    int e = find(y);
    if(s != e)
    {
        per[s] = e;
    }
}
int main()
{
    int T;

    scanf("%d",&T);
    while(T--)
    {
        scanf("%d%d",&n,&m);
        init();
        int a,b;
        for(int i = 1; i <= m; i ++)
        {
            scanf("%d%d",&a,&b);
            join(a,b);
        }
        int cnt = 0;
        for(int i = 1; i <= n; i ++)
        {
            if(per[i] == i)
                cnt ++;
        }
        printf("%d\n",cnt);
    }
    return 0;
}

如有错误，欢迎指出~