PKU1611--并查集Kruskar算法实现最小生成树源码

 

以下代码是使用java实现的pku1611，已经AC，算法具体可以参考并查集那篇。

import java.util.Scanner;
public class pku1611 {
        static int f[];
        static int r[];
        static void Make_Set(int n){
            for(int i=0;i                f[i]=i;
                r[i]=1;
            }
        }
        static int Find_Set(int i){
            if(f[i]==i) return i;
            f[i]=Find_Set(f[i]);
            return f[i];
        }
        static void Union(int x,int y){
            int a=Find_Set(x);
            int b=Find_Set(y);
            if(a==b) return;
            if(r[a]>r[b]){

                f[b]=a;
                r[a]+=r[b];
            }
            else{
                f[a]=b;
                r[b]+=r[a];
            }
        }
        public static void main(String argvs[]){
            Scanner in=new Scanner(System.in);
            int m,n,i,first,num,j,t;
            while(in.hasNext()){
                n=in.nextInt();
                m=in.nextInt();
                f=new int[n];
                r=new int[n];
                if(n==0&&m==0) break;
                Make_Set(n); 
                for(i=0;i<m;i++){
                    num=in.nextInt();
                    first=in.nextInt();
                    for(j=0;j<num-1;j++){
                        t=in.nextInt();
                        Union(first,t);
                    }
                }
                System.out.println(r[Find_Set(0)]);
            }
        }
}