Tietoverkko

#include <bits/stdc++.h>

using namespace std;

long speed_total = 0;
vector<pair<short, int>> v[200001];

void search(short s, short e, int speed) {
    if (speed != 1000000000) {
        speed_total += speed;
    }

    for (auto u : v[s]) {
        if (u.first != e) {
            search(u.first, s, min(speed, u.second));
        }
    }
}

int main() {
    short l;
    cin >> l;

    short a, b;
    int x;

    for (short i = 1; i < l; i++) {
        cin >> a >> b >> x;
        v[a - 1].push_back({b - 1, x});
        v[b - 1].push_back({a - 1, x});
    }

    for (short j = 0; j < l; j++) {
        search(j, j, 1000000000);
    }

    cout << (speed_total / 2) << "\n";

    return 0;
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: TIME LIMIT EXCEEDED