Submission #1253881

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253881		anfi	Cyberland (APIO23_cyberland)	C++20	15 / 100	328 ms	7996 KiB

cyberland

#include<bits/stdc++.h>
using namespace std;
const double INF = 1e18;

double solve(int n, int m, int k, int h, vector<int> x, vector<int> y, vector<int> c, vector<int> a) {
    // Batasi penggunaan diskon
    k = min(k, 100);
    
    // Inisialisasi graf
    vector<vector<pair<int, int>>> adj(n);
    for (int i = 0; i < m; i++) {
        adj[x[i]].push_back({y[i], c[i]});
        adj[y[i]].push_back({x[i], c[i]});
    }

    // Inisialisasi state
    vector<double> dist(n, INF);
    vector<double> temp(n, INF);
    double ans = INF;

    // Iterasi 0: tanpa diskon
    temp[0] = 0.0;
    priority_queue<pair<double, int>, vector<pair<double, int>>, greater<>> pq;
    pq.push({0.0, 0});
    
    while (!pq.empty()) {
        auto [cost, u] = pq.top();
        pq.pop();
        
        // Skip jika sudah ada cost yang lebih baik
        if (abs(cost - temp[u]) > 1e-9) continue;
        
        // Update jawaban jika mencapai tujuan
        if (u == h) ans = min(ans, cost);
        
        // Proses tetangga
        for (auto [v, w] : adj[u]) {
            double new_cost = cost + w;
            
            // Penanganan khusus node tipe 0
            if (a[v] == 0 && new_cost > 1e-9) new_cost = 0.0;
            
            if (new_cost < temp[v]) {
                temp[v] = new_cost;
                pq.push({new_cost, v});
            }
        }
    }
    
    // Jika tidak ada jalur di iterasi 0
    if (temp[h] >= INF) return -1.0;
    
    // Update state untuk iterasi diskon
    dist = temp;
    ans = min(ans, dist[h]);

    // Iterasi diskon (1 hingga k)
    for (int j = 1; j <= k; j++) {
        // Reset state sementara
        fill(temp.begin(), temp.end(), INF);
        priority_queue<pair<double, int>, vector<pair<double, int>>, greater<>> pq;
        
        // Inisialisasi dari state sebelumnya
        for (int i = 0; i < n; i++) {
            if (dist[i] >= INF) continue;
            
            // Penanganan node khusus
            if (a[i] == 0) {
                temp[i] = 0.0;
                pq.push({0.0, i});
            } else if (a[i] == 2) {
                double discounted = dist[i] / 2.0;
                if (discounted < temp[i]) {
                    temp[i] = discounted;
                    pq.push({discounted, i});
                }
            }
        }
        
        // Jalankan Dijkstra
        while (!pq.empty()) {
            auto [cost, u] = pq.top();
            pq.pop();
            
            // Skip jika sudah ada cost yang lebih baik
            if (abs(cost - temp[u]) > 1e-9) continue;
            
            // Update jawaban jika mencapai tujuan
            if (u == h) ans = min(ans, cost);
            
            // Proses tetangga
            for (auto [v, w] : adj[u]) {
                double new_cost = cost + w;
                
                // Penanganan khusus node tipe 0
                if (a[v] == 0 && new_cost > 1e-9) new_cost = 0.0;
                
                if (new_cost < temp[v]) {
                    temp[v] = new_cost;
                    pq.push({new_cost, v});
                }
            }
        }
        
        // Update state untuk iterasi berikutnya
        dist = temp;
    }

    return (ans < INF - 1e9) ? ans : -1.0;
}

• Subtask 1: 0 / 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