Submission #337861

#	Time	Username	Problem	Language	Result	Execution time	Memory
337861		KazamaHoang	Bosses (BOI16_bosses)	C++14	100 / 100	1413 ms	1132 KiB

bosses

/* -> Written by <-
   -----------
  K_A_Z_A_M_A
  ___________
      _    |
  |   (^_^)   |
  |  /( | )\  |
  |____|_|____|
    H O A N G
*/

#include <bits/stdc++.h>

#define Task            ""
#define F               first
#define S               second
#define pb              push_back
#define bit(x, i)       ((x >> (i)) & 1)
#define inf             1e9 + 7
#define INF             1e18 + 7
#define ll              long long
#define pii             pair <int, int>
#define debug(x)        cerr << #x << " is " << x << "\n";

using namespace std;

const int MOD = 1e9 + 7;
const int maxn = 5005;

int n;
vector <int> ke[maxn], e[maxn];
bool dd[maxn];
int q[maxn];
int d[maxn];

void bfs(int u){
    int l = 0, r = 1;
    q[1] = u;
    dd[u] = -1;
    while (l < r){
        u = q[++l];
        for (auto v : ke[u])
            if (dd[v] == 0){
                dd[v] = 1;
                e[u].pb(v);
                q[++r] = v;
            }
    }
}

void dfs(int u){
    d[u] = 1;
    for (auto v : e[u]){
        dfs(v);
        d[u] += d[v];
    }
}

int OK(){
    int s = 0;
    for (int i = 1; i <= n; ++ i)
        if (d[i] == inf) return 0;
        else s += d[i];
    return s;
}

void Solve(){
    cin >> n;
    for (int i = 1; i <= n; ++ i){
        int x; cin >> x;
        for (int j = 1; j <= x; ++ j){
            int y; cin >> y;
            ke[y].pb(i);
        }
    }
    int res = inf;
    for (int i = 1; i <= n; ++ i){
        memset(dd, 0, sizeof(dd));
        for (int j = 1; j <= n; ++ j) e[j].clear();
        fill(d + 1, d + 1 + n, inf);
        bfs(i);
        dfs(i);
        int s = OK();
        if (s == 0) continue;
        res = min(res, s);
    }
    cout << res << "\n";
}

int main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    if(fopen(Task".inp", "r")){
        freopen(Task".inp","r",stdin);
        freopen(Task".out","w",stdout);
    }
    int test_case = 1;
    // cin >> test_case;
    while (test_case --){
        Solve();
    }

    return 0;
}

Compilation message (stderr)

bosses.cpp: In function 'int main()':
bosses.cpp:93:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   93 |         freopen(Task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:94:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   94 |         freopen(Task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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