Submission #773397

#	Time	Username	Problem	Language	Result	Execution time	Memory
773397		Jomnoi	Shortcut (IOI16_shortcut)	C++17	0 / 100	2089 ms	1620 KiB

shortcut

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

const int MAX_N = 6005;
const long long INF = 1e18 + 7;

int n;
multiset <pair <int, int>> graph[MAX_N];
long long dist[MAX_N][MAX_N];
bool visited[MAX_N];

void bfs(int s) {
    for (int i = 0; i < 2 * n; i++) {
        dist[s][i] = INF;
        visited[i] = false;
    }

    priority_queue <pair <long long, int>> pq;
    pq.emplace(0, s);
    dist[s][s] = 0;
    while (!pq.empty()) {
        auto [d, u] = pq.top();
        pq.pop();

        if (visited[u] == true) continue;
        visited[u] = true;

        for (auto [v, w] : graph[u]) {
            if (visited[v] == false and dist[s][u] + w < dist[s][v]) {
                dist[s][v] = dist[s][u] + w;
                pq.emplace(-dist[s][v], v);
            }
        }
    }
}

long long find_shortcut(int n, vector <int> l, vector <int> d, int c) {
    ::n = n;
    for (int i = 0; i < n - 1; i++) {
        graph[i].emplace(i + 1, l[i]);
        graph[i + 1].emplace(i, l[i]);
    }
    for (int i = 0; i < n; i++) {
        graph[i].emplace(n + i, d[i]);
        graph[n + i].emplace(i, d[i]);
    }

    long long ans = INF;
    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            graph[i].emplace(j, c);
            graph[j].emplace(i, c);

            for (int i = 0; i < 2 * n; i++) bfs(i);
            long long max_dist = 0;
            for (int i = 0; i < 2 * n; i++) {
                for (int j = 0; j < 2 * n; j++) max_dist = max(max_dist, dist[i][j]);
            }

            ans = min(ans, max_dist);

            graph[i].erase(graph[i].lower_bound(make_pair(j, c)));
            graph[j].erase(graph[j].lower_bound(make_pair(i, c)));
        }
    }
    return ans;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 14
• Subtask 3: 0 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3