Submission #900610

#	Time	Username	Problem	Language	Result	Execution time	Memory
900610		Trisanu_Das	Cyberland (APIO23_cyberland)	C++17	100 / 100	811 ms	13448 KiB

cyberland

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

using vi = vector<int>;
using ar = pair<double, int>;

const int mxN = 1e5 + 10;
const double LINF = 1e105;

double ans;
int n, m, h;
bool vis[mxN];
double dis[mxN], dis2[mxN];
vector<pair<int, int>> adj[mxN];
priority_queue<ar, vector<ar>, greater<ar>> pq;

void dijkstra() {
    fill(vis, vis + n + 1, 0);
    for (int i = 0; i < n; i++) if (dis[i] < LINF) pq.push({dis[i], i});
    while (!pq.empty()) {
        auto [D, a] = pq.top();
        pq.pop();
        if (vis[a] or a == h) continue;
        vis[a] = 1;
        for (auto [b, w] : adj[a]) if (dis[b] > dis[a] + w) dis[b] = dis[a] + w, pq.push({dis[b], b});
    }
    ans = min(ans, dis[h]);
}

double solve(int N, int M, int K, int H, vi x, vi y, vi c, vi A) {
    n = N, m = M, h = H, K = min(K, 67);
    fill(dis, dis + n, LINF);
    ans = LINF;
    for (int i = 0; i < n; i++) adj[i].clear();
    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]});
    dis[0] = 0;
    dijkstra();
    if (dis[h] >= LINF) return -1;
    for (int i = 0; i < n; i++) if (dis[i] != LINF) dis[i] = A[i] && i ? LINF : 0;
    for (int i = 0; i <= K; i++) {
        dijkstra();
        fill(dis2, dis2 + n, LINF);
        for (int j = 0; j < n; j++) if (A[j] > 1) for (auto [u, w] : adj[j]) dis2[u] = min(dis2[u], dis[j] / 2 + w);
        for (int j = 0; j < n; j++) dis[j] = dis2[j];
    }

    return ans;
}

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