Submission #870154

#	Time	Username	Problem	Language	Result	Execution time	Memory
870154		Pannda	Robot (JOI21_ho_t4)	C++17	34 / 100	3055 ms	34384 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define int long long
const long long INF = (int)4e18;

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
//    freopen("inp.inp", "r", stdin);
//    freopen("out.out", "w", stdout);

    int n, m;
    cin >> n >> m;
    vector<vector<array<int, 3>>> adj(n);

    for (int i = 0; i < m; i++) {
        int u, v, color, cost;
        cin >> u >> v >> color >> cost;
        u--;
        v--;
        adj[u].push_back({ v, color, cost });
        adj[v].push_back({ u, color, cost });
    }

    map<array<int, 2>, long long> dist; // (u, par) -> distance
    priority_queue<array<long long, 3>, vector<array<long long, 3>>, greater<>> pq;
    dist[{0, -1}] = 0;
    pq.push({0, 0, -1});

    while (!pq.empty()) {
        auto [d, u, p] = pq.top();
        pq.pop();
        if (dist.count({u, p}) && dist[{u, p}] != d) continue;
        map<int, long long> mp; // color to sum of cost
        for (auto [v, color, cost] : adj[u]) {
            if (v == p) continue;
            mp[color] += cost;
        }
        for (auto [v, color, cost] : adj[u]) {
            if (v == p) continue;
            if (!dist.count({v, u}) || dist[{v, u}] > d + cost) {
                dist[{v, u}] = d + cost;
                pq.push({ d + cost, v, u });
            }
            if (!dist.count({v, -1}) || dist[{v, -1}] > d + mp[color] - cost) {
                dist[{v, -1}] = d + mp[color] - cost;
                pq.push({ d + mp[color] - cost, v, -1 });
            }
        }
    }

    long long ans = INF;
    for (auto [arr, d] : dist) {
        auto [u, p] = arr;
        if (u == n - 1) {
            ans = min(ans, d);
        }
    }
    if (ans == INF) ans = -1;
    cout << ans << '\n';
}

• Subtask 1: 34 / 34
• Subtask 2: 0 / 24
• Subtask 3: 0 / 42