Submission #725132

#	Time	Username	Problem	Language	Result	Execution time	Memory
725132		buffering	Bosses (BOI16_bosses)	C++17	100 / 100	624 ms	656 KiB

bosses

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

void IO(string s = "")
{
    if (s == "")
    {
        freopen("input.txt", "r", stdin);
        freopen("output 2.txt", "w", stdout);
    }
    if (s != "")
    {
        freopen((s + ".in").c_str(), "r", stdin);
        freopen((s + ".out").c_str(), "w", stdout);
    }
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    //IO();

    int n; cin >> n;
    
    vector<vector<int>> adj(n);

    for (int i = 0; i < n; i++) {
        int m; cin >> m;
        for (int j = 0; j < m; j++) {
            int v; cin >> v;
            v--;
            adj[v].push_back(i);
        }
    }

    long long ans = 1e9;

    for (int i = 0; i < n; i++) {
        vector<int> depths(n, -1);
        queue<int> q;
        q.push(i);
        depths[i] = 0;
        while (!q.empty()) {
            int node = q.front(); q.pop();
            for (int v: adj[node]) {
                if (depths[v] == -1) {
                    depths[v] = depths[node] + 1;
                    q.push(v);
                }
            }
        }
        if (*min_element(depths.begin(), depths.end()) == 0) {
            long long curr = n;
            for (auto d: depths) curr += d;
            ans = min(ans, curr);
        }
    }

    cout << ans << endl;

}

Compilation message (stderr)

bosses.cpp: In function 'void IO(std::string)':
bosses.cpp:8:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |         freopen("input.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:9:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |         freopen("output 2.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:13:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |         freopen((s + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:14:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |         freopen((s + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 45 / 45
• Subtask 3: 33 / 33