PKU1611--并查集Kruskar算法实现最小生成树源码

1.  

   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)]);
               }
           }
   }