Submission #575514

#	Time	Username	Problem	Language	Result	Execution time	Memory
575514		Elias	Shortcut (IOI16_shortcut)	C++17	0 / 100	2074 ms	300 KiB

shortcut

#include <bits/stdc++.h>

#ifndef _DEBUG
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#include "shortcut.h"
#endif

using namespace std;
#define int long long

vector<vector<pair<int, int>>> adj;

vector<int> dijkstra(int s)
{
    vector<int> dist(adj.size(), -1);
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    pq.push({0, s});

    while (!pq.empty())
    {
        auto [d, i] = pq.top();
        pq.pop();

        if (dist[i] != -1)
            continue;

        dist[i] = d;

        for (auto [c, p] : adj[i])
        {
            if (dist[c] == -1)
                pq.push({d + p, c});
        }
    }

    return dist;
}

long long dia()
{
    int longest = 0;
    for (int i = 0; i < adj.size(); i++)
    {
        vector<int> dists;
        dists = dijkstra(i);
        longest = max(longest, *max_element(dists.begin(), dists.end()));
    }

    return longest;
}

long long find_shortcut(signed n, vector<signed> l, vector<signed> d, signed c)
{
    adj = vector<vector<pair<int, int>>>(2 * n);

    for (int i = 0; i < n - 1; i++)
    {
        adj[i].push_back({i + 1, l[i]});
        adj[i + 1].push_back({i, l[i]});
    }

    for (int i = 0; i < n; i++)
    {
        adj[i].push_back({i + n, d[i]});
        adj[i + n].push_back({i, d[i]});
    }

    long long best = dia();

    for (int i = 0; i < n; i++)
        for (int j = i + 1; j < n; j++)
        {
            adj[i].push_back({j, c});
            adj[j].push_back({i, c});

            best = min(best, dia());

            adj[i].pop_back();
            adj[j].pop_back();
        }

    return best;
}

Compilation message (stderr)

shortcut.cpp: In function 'long long int dia()':
shortcut.cpp:44:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::vector<std::pair<long long int, long long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for (int i = 0; i < adj.size(); i++)
      |                     ~~^~~~~~~~~~~~

• 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