kruskal 算法模板

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
struct node
{
    int u,v,w;
}q[200001];
int bin[50001];
int n,m,ans;
int cmp(const void *a,const void *b)
{
    struct node *x;
    struct node *y;
    x = (struct node *)a;
    y = (struct node *)b;
    return x->w - y->w;
}
int find(int x)
{
    int r,k,j;
    r = x;
    while(bin[r]!=r)
    r = bin[r];
    j = x;
    while(j!=r)
    {
        k = bin[j];
        bin[j] = r;
        j = k;
    }
    return r;
}
void kruskal()
{
    int i;
    for(i = 1;i<=n;i++)
    {
        bin[i] = i;
    }
    for(i = 0;i<m;i++)
    {
        int uu = find(q[i].u);
        int vv = find(q[i].v);
        if(uu!=vv)
        {
            bin[uu] = vv;
            ans+=q[i].w;
        }
    }
    printf("%d\n",ans);
}
int main()
{
    int i,j;
    while(~scanf("%d%d",&n,&m))
    {
        ans = 0;
        for(i = 0;i<m;i++)
        {
            scanf("%d%d%d",&q[i].u,&q[i].v,&q[i].w);
        }
        qsort(q,m,sizeof(q[0]),cmp);
        kruskal();
    }
    return 0;
}