DMOPC '14 Exam Time P4 - Exam Delay

    1#include <bits/stdc++.h>
    2using namespace std;
    3typedef long long ll;
    4const int inf = 1e9;
    5const long long INF = 1e17; //❄️
    6int main() {
    7    ios::sync_with_stdio(0); cin.tie(0); 
    8    int n, m; cin >> n >> m;
    9    vector<vector<pair<double, int>>> adj(n + 1);
    10    for (int i = 0; i < m; i++) {
    11        int u, v, d, s; cin >> u >> v >> d >> s;
    12        double w = (double) d / (double) s * (double) 60; //minute
    13        adj[u].emplace_back(w, v);
    14        adj[v].emplace_back(w, u);
    15    }
    16    vector<pair<double, int>> dist(n + 1, make_pair(inf, inf));
    17    dist[1] = {(double) 0, 0};
    18    priority_queue<tuple<double, int, int>, vector<tuple<double, int, int>>, greater<tuple<double, int, int>>> pq;
    19    // same dist, same edge count
    20    pq.emplace(0, 0, 1);
    21    while (!pq.empty()) {
    22         auto[w, e, u] = pq.top(); pq.pop();
    23         if (u == n) break;
    24        //  if (w > dist[u].first) continue;
    25         for (auto[wt, v] : adj[u]) {
    26            if (dist[v].first > wt + w) {
    27                dist[v].first = wt + w;
    28                dist[v].second = e + 1;
    29                pq.emplace(dist[v].first, e + 1, v);
    30            } else if(dist[v].first == wt + w && e + 1 < dist[v].second) {
    31                dist[v].second = e + 1;
    32                pq.emplace(dist[v].first, e + 1, v);
    33            }
    34         }
    35    }
    36    cout << dist[n].second << '\n';
    37    cout << round(dist[n].first / 3) << '\n';
    38    return 0;
    39}