mapa.cpp

#include <cstdio>
#include <vector>
#include <cassert>
#define MAXN 100100
using namespace std;

typedef long long ll;

int n;
bool visited[MAXN];
vector<int> graph[MAXN];

int last; //quantidade de componentes conexas
ll qtt[MAXN];

void dfs(int x){

    qtt[last]++;
    visited[x] = true;

    for(int i = 0;i < graph[x].size();i++){
        if(!visited[ graph[x][i] ])
            dfs(graph[x][i]);
    }
}

int main(){

    scanf("%d", &n);
    for(int i = 1;i < n;i++){
        int a, b, c;
        scanf("%d %d %d", &a, &b, &c);

        if(c) continue;

        graph[a].push_back(b);
        graph[b].push_back(a);
    }

    for(int i = 1;i <= n;i++) visited[i] = 0;
    for(int i = 1;i <= n;i++){
        if(!visited[i]){
            last++;
            dfs(i);
        }
    }

    ll answer = 0LL;
    for(int i = 1;i <= last;i++) answer += qtt[i];
    answer *= answer;
    for(int i = 1;i <= last;i++) answer -= qtt[i]*qtt[i];
    answer /= 2;

    printf("%lld\n", answer);

    return 0;
}