Submission #1057156

#	Time	Username	Problem	Language	Result	Execution time	Memory
1057156		vjudge1	Bosses (BOI16_bosses)	C++17	100 / 100	507 ms	1112 KiB

bosses

#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
const i64 oo64 = 2e18;
const int MAXN = 5e3 + 5;
 
int N;
vector<int> adj[MAXN];
vector<int> g[MAXN];
int dist[MAXN];
i64 ans = oo64;
 
void BFS(int r) {
    for(int i = 1; i <= N; i++) {
        g[i].clear();
        dist[i] = N + 1;
    }
    queue<int> Q;
    Q.emplace(r);
    dist[r] = 1;
    while(!Q.empty()) {
        int u = Q.front();
        Q.pop();
        for(int v : adj[u]) {
            if(dist[v] > dist[u] + 1) {
                g[u].emplace_back(v);
                dist[v] = dist[u] + 1;
                Q.emplace(v);
            }
        }
    }
    i64 res = 0;
    for(int i = 1; i <= N; i++) {
        if(dist[i] > N) return;
        res += dist[i];
    }
    ans = min(ans, res);
}
 
signed main() {
#define TASK "code"
 
    if (fopen(TASK ".inp", "r")) {
        freopen(TASK ".inp", "r", stdin);
        freopen(TASK ".out", "w", stdout);
    }
 
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 
    cin >> N;
    for(int i = 1; i <= N; i++) {
        int sz = 0;
        cin >> sz;
        for(int j = 1; j <= sz; j++) {
            int x = 0;
            cin >> x;
            adj[x].emplace_back(i);
        }
    }
    for(int i = 1; i <= N; i++) BFS(i);
    cout << ans;
 
    return (0 ^ 0);
}

Compilation message (stderr)

bosses.cpp: In function 'int main()':
bosses.cpp:44:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |         freopen(TASK ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:45:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |         freopen(TASK ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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