Submission #1272944

#	Time	Username	Problem	Language	Result	Execution time	Memory
1272944		duckindog	Shortcut (IOI16_shortcut)	C++20	0 / 100	1 ms	336 KiB

shortcut

#include <bits/stdc++.h>

#include "shortcut.h"

using namespace std;

const long long MAX = 1'000'000'000'000'000'000;

const int N = 500 + 10;
vector<pair<int, int>> ad[N];

long long find_shortcut(int n, vector<int> l, vector<int> d, int c) {
    for (int i = 0; i < n - 1; ++i) { 
        ad[i].push_back({i + 1, l[i]});
        ad[i + 1].push_back({i, l[i]});
    }
    auto bfs = [&](int st) { 
        vector<long long> f(n, MAX);
        f[st] = 0;
        queue<int> q({st});
        while (q.size()) { 
            auto u = q.front(); q.pop();
            for (const auto& [v, w] : ad[u]) { 
                if (f[v] > f[u] + w) { 
                    f[v] = f[u] + w;
                    q.push(v);
                }
            }
        }
        
        int ret = -1;
        for (int i = 0; i < n; ++i) { 
            if (i != st && (ret == -1 || f[i] + d[i] > f[ret] + d[ret])) ret = i;
        }
        return make_pair(ret, f[ret] + d[ret] + d[st]);
    };

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

            int st = bfs(0).first;
            answer = min(answer, bfs(st).second);

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

    return answer;
}

Compilation message (stderr)

shortcut.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~
shortcut_c.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~

• 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