HDOJ-1213(简单并查集)

How many tables

HDOJ-1213

#include<iostream>
#include<cstring>
#include<cstdio>
#include<string>
#include<algorithm>
#include<cmath>
#include<vector>
#include<map>
using namespace std;
const int maxn=1004;
int n,m;
int set[maxn];
int rank1[maxn];//rank1[i]表示i的深度
int find(int x){
    if(x==set[x])
        return set[x];
    return set[x]=find(set[x]);
}
void merge(int a,int b){
    int ta=find(a);
    int tb=find(b);
    if(ta!=tb){
        if(rank1[ta]<rank1[tb]){
            set[ta]=tb;
        }else{
            set[tb]=ta;
            if(rank1[ta]==rank1[tb]){
                rank1[ta]++;
            }
        }
    }else return;
}
int main(){
    int t;
    cin>>t;
    while(t--){
        cin>>n>>m;
        for(int i=1;i<=n;i++){
            set[i]=i;
            rank1[i]=0;
        }
        for(int i=0;i<m;i++){
            int x,y;
            cin>>x>>y;
            merge(x,y);
        }
        int sum=0;
        for(int i=1;i<=n;i++){
            if(set[i]==i){
                sum++;
            }
        }
        cout<<sum<<endl;
    }
    return 0;
}