4wigI4 - Online C++0x Compiler & Debugging Tool

#include <iostream>
#include <vector>
#include <queue>
using namespace std;

pair<vector<int>, vector<int>>
bfsMaxFive(int n, const vector<vector<int>>& g, const vector<int>& val) {
    vector<int> dist(n+1, -1), five(n+1, -1);
    queue<int> q;
    dist[1] = 0;
    five[1] = (val[1] == 5 ? 1 : 0);
    q.push(1);

    while (!q.empty()) {
        int v = q.front(); q.pop();
        for (int u : g[v]) {
            int add = (val[u] == 5 ? 1 : 0);
            if (dist[u] == -1) {
                dist[u] = dist[v] + 1;
                five[u] = five[v] + add;
                q.push(u);
            } else if (dist[u] == dist[v] + 1) {
                if (five[v] + add > five[u]) five[u] = five[v] + add;
            }
        }
    }
    return {dist, five};
}

int main() {


    int n, m;
    cin >> n >> m;                  // nodes, edges
    vector<int> val(n+1);
    for (int i = 1; i <= n; ++i) cin >> val[i];  // each is 0 or 5

    vector<vector<int>> g(n+1);
    for (int i = 0; i < m; ++i) {
        int u, v; cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    auto [dist, five] = bfsMaxFive(n, g, val);

    // print results (1..n)
    for (int i = 1; i <= n; ++i) {
        cout << dist[i] << " " << five[i] << "\n";
    }
    return 0;
}