Submission #338068

#	Time	Username	Problem	Language	Result	Execution time	Memory
338068		theshadow_04	Bosses (BOI16_bosses)	C++14	67 / 100	1536 ms	3180 KiB

bosses

// V T An
#include <bits/stdc++.h>
#define Task "BOSSES"
#define pb push_back
#define F first
#define S second

using namespace std;

const int maxn = 50005;

int n;
vector<int> a[maxn], ke[maxn];
int dd[maxn];
int ans = 2e9, f[maxn];
int Q[maxn], bot = 1, top = 0;

void BFS(int s) {
    bot = 1, top = 0;
    Q[++ top] = s;
    dd[s] = 1;
    while(bot <= top) {
        int u = Q[bot ++];
        for(auto v : a[u]) {
            if(!dd[v]) {
                dd[v] = 1;
                ke[u].pb(v);
                Q[++ top] = v;
            }
        }
    }
}

void DFS(int u) {
    f[u] = 1;
    for(auto v : ke[u]) {
        if(!f[v]) {
            DFS(v);
            f[u] += f[v];
        }
    }
}

void Solve(int u) {
    for(int i = 1; i <= n; ++ i) ke[i].clear(), f[i] = dd[i] = 0;
    BFS(u);
    DFS(u);
    int total = 0;
    for(int i = 1; i <= n; ++ i) {
        if(!f[i]) return;
        total += f[i];
    }
    ans = min(ans, total);
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    if(fopen(Task".inp", "r")) {
        freopen(Task".inp", "r", stdin);
        freopen(Task".out", "w", stdout);
    }
    cin >> n;
    for(int i = 1; i <= n; ++ i) {
        int k; cin >> k;
        while(k --) {
            int x; cin >> x;
            a[x].pb(i);
        }
    }

    for(int i = 1; i <= n; ++ i) {
        Solve(i);
    }

    cout << ans;
}

// CHY-AKAV

Compilation message (stderr)

bosses.cpp: In function 'int main()':
bosses.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   60 |         freopen(Task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   61 |         freopen(Task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 45 / 45
• Subtask 3: 0 / 33