Kruskal

#include<cstdio>
#include<ctime>
#include<iostream>
#include<algorithm>

using namespace std;

struct road{
 int from;
 int to;
 int weath;
};
road a[105];

int n,e,tot;
int r1,r2,father[105];

int cmp(const road&b,const road&c){
 if(b.weath<c.weath)return 1;
 else return 0;
}

int find(int x){
 if(father[x]!=x)father[x]=find(father[x]);
 return father[x];
}

void unionn(int r1,int r2){
 father[r2]=r1;
}

int main(){
 scanf("%d%d",&n,&e);
 for(int i=1;i<=e;i++){
  scanf("%d%d%d",&a[i].from,&a[i].to,&a[i].weath);
 }
 for(int i=1;i<=n;i++){
  father[i]=i;
 }
 sort(a+1,a+1+e,cmp);
 for(int i=1;i<=n;i++){
  tot++;
  if(father[a[tot].from]!=father[a[tot].to]){
   printf("%d %d\n",a[tot].from,a[tot].to);
   r1=find(a[tot].from);
   r2=find(a[tot].to);
   if(r1!=r2)unionn(r1,r2);
  }
  else continue;
 }
 printf("Time used=%0.2lf\n",(double)clock()/CLOCKS_PER_SEC);
 return 0;
}  

Kruskal

原文：http://www.cnblogs.com/cdqzfredrick/p/5303287.html