Submission #1151215

#	Time	Username	Problem	Language	Result	Execution time	Memory
1151215		turska	Cyberland (APIO23_cyberland)	C++20	44 / 100	28 ms	8520 KiB

cyberland

#include "cyberland.h"


#include <bits/stdc++.h>
#include <queue>
using namespace std;
using ll = long long;
const ll INF = 1e18;
vector<vector<array<int, 2>>> adj;


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

double solve(int N, int M, int K, int H, std::vector<int> x, std::vector<int> y, std::vector<int> c, std::vector<int> arr) {
    adj.assign(N, {});
    for (int i=0; i<M; i++) {
        int u = x[i], v=y[i], w=c[i];
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }
    double ans = INF; 
    vector<char> vis(N);
    vis[0] = true;
    queue<int> q;
    q.push(0);
    while (!q.empty()) {
        int v= q.front(); q.pop();
        for (auto [u, _]: adj[v]) {
            if (!vis[u] && u!=H) {
                vis[u] = true;
                q.push(u);
            }
        }
    };
    vector<int> starts = {0};
    for (int i=1; i<N; i++) if (vis[i] && arr[i]==0) starts.push_back(i);

    vector<ll> d0 = dijkstra(starts, N), d1 = dijkstra({H}, N);
    if (d1[0]==INF) return -1;

    for (auto v: starts) ans = min(ans, (double)d1[v]);
    for (int i=0; i<N; i++) {
        if (arr[i]!=2 || d0[i]==INF || d1[i]==INF) continue;
        int cnt = K;
        double dist = d0[i];
        while (dist>1e-9 && cnt) {
            dist /= 2;
            cnt--;
        }
        ans = min(ans, dist+d1[i]);
    }
    return ans;
}

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