Submission #1219419

#	Time	Username	Problem	Language	Result	Execution time	Memory
1219419		niwrad	Robot (JOI21_ho_t4)	C++20	0 / 100	575 ms	49788 KiB

Main

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


struct edge {
    int to, c, id;
    long long p;
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, m;
    cin >> n >> m;
    vector<vector<edge>> graph(n);
    vector<map<int, long long>> color(n);
    vector<map<int, int>> vis(n);
    vector<edge> edges;
    vector<map<int, long long>> dis(n);
    for (int i = 0; i < m; i++) {
        int a, b, c; long long p;
        cin >> a >> b >> c >> p;
        a--, b--;
        edge e1; edge e2;
        e1.id = i * 2; e2.id = i * 2 + 1;
        e1.to = b; e2.to = a; e1.c = e2.c = c; e1.p = e2.p = p;
        graph[a].push_back(e1); graph[b].push_back(e2);
        edges.push_back(e1); edges.push_back(e2);
    }
    for (int i = 0; i < n; i++) {
        for (auto eg : graph[i]) {
            color[i][eg.c] += eg.p;
        }
    }
    dis[0][-1] = 0;
    priority_queue<pair<long long, pair<int, int>>> pq;
    pq.push({0, {0, -1}});
    while (pq.size() > 0) {
        auto t = pq.top();
        pq.pop();
        if (vis[t.second.first][t.second.second]) {
            continue;
        }
        vis[t.second.first][t.second.second] = 1;
        long long d = dis[t.second.first][t.second.second];
        for (auto eg: graph[t.second.first]) {
            long long cost = color[t.second.first][eg.c];
            if (t.second.second >= 0 && eg.c == edges[t.second.second].c) {
                cost -= edges[t.second.second].p;
            }
            if (dis[eg.to].find(-1) == dis[eg.to].end() || d + cost - eg.p < dis[eg.to][-1]) {
                dis[eg.to][-1] = d + cost - eg.p;
                pq.push({-dis[eg.to][-1], {eg.to, -1}});
            }
            dis[eg.to][eg.id] = d + eg.p;
            pq.push({-dis[eg.to][eg.id], {eg.to, eg.id}});
        }
    }
    long long md = 1e18;
    for (auto it = dis[n - 1].begin(); it != dis[n - 1].end(); it++) {
        md = min(md, it->second);
    }
    if (md == 1e18) {
        cout << "-1\n";
    } else {
        cout << md << "\n";
    }
}

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