看discuss发现样例有问题

#include<cstdio>
#include<algorithm>
#define INF 0x3f3f3f3f
using namespace std;
struct Edge
{
    int l,r;
    int val;
} edge[15055],res[1055];
bool cmp(const Edge x,const Edge y)
{
    return x.val<y.val;
}
int V,E;
int tree[1005];
int find(int x)
{
    return tree[x]==x?x:tree[x]=find(tree[x]);
}
void Kruskal()
{
    int ans = 0,cnt = 0,Max = 0;
    for(int i = 1; i<=V; ++i)
        tree[i] = i;
    for(int i = 0; i<E; ++i)
    {
        int x = find(edge[i].l);
        int y = find(edge[i].r);
        if(x!=y)
        {
            tree[x] = y;
            res[cnt].l = edge[i].l;
            res[cnt].r = edge[i].r;
            res[cnt++].val = edge[i].val;
        }
        if(cnt==V-1)
            break;
    }
    printf("%d\n",res[cnt-1].val);
    printf("%d\n",cnt);
    for(int i = 0; i<cnt; ++i)
        printf("%d %d\n",res[i].l,res[i].r);
}
int main()
{
    while(~scanf("%d%d",&V,&E))
    {
        for(int i = 0; i<E; ++i)
            scanf("%d%d%d",&edge[i].l,&edge[i].r,&edge[i].val);
        sort(edge,edge+E,cmp);
        Kruskal();
    }
    return 0;
}