2019暑假集训 走廊泼水节

#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
int t,n,fa[6050],book[6050];
struct edge
{
    int u,v,c;
};
bool cmp(edge a,edge b)
{
    return a.c<b.c;
}//按边权排序
int f(int o)
{
    if(fa[o]==o)return o;
    return fa[o]=f(fa[o]);
}
void u(int a,int b)
{
    if(a<b)book[f(a)]+=book[f(b)],fa[f(b)]=fa[f(a)];
    else book[f(b)]+=book[f(a)],fa[f(a)]=fa[f(b)];
}
int main()
{
    scanf("%d",&t);
    while(t--)
    {
        int ans=0;
        memset(fa,0,sizeof fa);
        memset(book,0,sizeof book);
        scanf("%d",&n);
        edge e[6050];
        for(int i=1;i<=n-1;i++)scanf("%d%d%d",&e[i].u,&e[i].v,&e[i].c);
        sort(e+1,e+n,cmp);
        for(int i=1;i<=n;i++)fa[i]=i,book[i]=1;
        for(int i=1;i<=n-1;i++)
        {
            ans+=(book[f(e[i].u)]*book[f(e[i].v)]-1)*(e[i].c+1);
            u(e[i].u,e[i].v);//Kruscal
        }
        printf("%d\n",ans);
    }
    return 0;
}