제출 #1191281

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1191281		just	Cyberland (APIO23_cyberland)	C++20	20 / 100	38 ms	14404 KiB

cyberland

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

#define vec vector
#define all(x) (x).begin(), (x).end()

double solve(int N, int M, int K, int H, vector<int> X, vector<int> Y, vector<int> C, vector<int> S) {
    const double INF = numeric_limits<double>::max();
    map<pair<int, int>, double> edges;
    vector<vector<pair<int, double>>> adj(N);
    for (int i = 0; i < M; i++) {
        int u = X[i], v = Y[i];
        double cost = static_cast<double>(C[i]);
        adj[u].push_back({v, cost});
        adj[v].push_back({u, cost});
        edges[{u, v}] = cost;
        edges[{v, u}] = cost;
    }

    vector<double> dist(N, INF);
    dist[0] = 0;
    priority_queue<pair<double, int>, vector<pair<double, int>>, greater<pair<double, int>>> pq;
    pq.push({0, 0});
    while (!pq.empty()) {
        auto [d, u] = pq.top();
        pq.pop();
        if (d > dist[u]) continue;
        for (auto [v, cost] : adj[u]) {
            if (dist[v] > d + cost) {
                dist[v] = d + cost;
                pq.push({dist[v], v});
            }
        }
    }

    if (dist[H] == INF) return -1;

    if (N == 2) {
        return dist[H];
    }

    // Subtask O1
    if (N == 3) {
        int other = (H == 1 ? 2 : 1);
        double result = INF;
        if (edges.count({0, H})) {
            result = edges[{0, H}];
        }

        if (edges.count({0, other}) && edges.count({other, H})) {
            if (S[other] == 0)
                result = min(result, edges[{other, H}]);
            if (S[other] == 1)
                result = min(result, dist[H]);
            if (S[other] == 2)
                result = min(result, edges[{0, other}] / 2.0 + edges[{other, H}]);
        }

        return result;
    }

    vector<double> backdist(N, INF);
    backdist[H] = 0;
    priority_queue<pair<double, int>, vector<pair<double, int>>, greater<pair<double, int>>> backpq;
    backpq.push({0, H});
    while (!backpq.empty()) {
        auto [d, u] = backpq.top();
        backpq.pop();
        if (d > backdist[u]) continue;
        for (auto [v, cost] : adj[u]) {
            if (backdist[v] > d + cost) {
                backdist[v] = d + cost;
                backpq.push({backdist[v], v});
            }
        }
    }
    if (backdist[0] == INF) return -1;

    double cost = backdist[0];
    for(int i = 0; i < N; i++) {
        if (S[i] == 0) {
            cost = min(cost, backdist[i]);
        }
    }

    return cost;
}

// signed main() {
//     cout << solve(3, 2, 30, 2, {1, 2}, {2, 0}, {12, 4}, {1, 2, 1});
// }

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 19
• Subtask 5: 7 / 7
• Subtask 6: 0 / 16
• Subtask 7: 0 / 29
• Subtask 8: 0 / 3