Submission #1270171

#	Time	Username	Problem	Language	Result	Execution time	Memory
1270171		quangminh412	Bosses (BOI16_bosses)	C++17	100 / 100	916 ms	1328 KiB

bosses

/*
  Ben Watson

  Quang Minh MasterDDDDD
*/

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

#define ll long long

const string name = "sharks";

void solve();
signed main()
{
    if (fopen((name + ".inp").c_str(), "r"))
    {
        freopen((name + ".inp").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    solve();

    return 0;
}

// main program
const ll oo = 0x3f3f3f3f3f3f3f3f;
const int maxn = 5001;

vector<int> leaders[maxn], childs[maxn], adj[maxn];
int n;

int vis[maxn];
ll val[maxn];
void DFS(int u)
{
    ll sum = 0;
    for (int v : adj[u])
    {
        DFS(v);
        sum += val[v];
    }
    val[u] = sum + 1;
}

ll compute(int root)
{
    for (int i = 1; i <= n; i++)
        childs[i].clear();
    for (int i = 1; i <= n; i++)
    {
        vis[i] = 0;
        val[i] = 0;
        if (i == root)
            continue;
        for (int x : leaders[i])
            childs[x].push_back(i);
    }

    for (int i = 1; i <= n; i++)
        adj[i].clear();
    queue<int> q;
    q.push(root);
    vis[root] = 1;
    while (!q.empty())
    {
        int u = q.front();
        q.pop();

        for (int v : childs[u])
        {
            if (vis[v] == 1)
                continue;

            vis[v] = 1;
            adj[u].push_back(v);
            q.push(v);
        }
    }
    DFS(root);
    ll res = 0;
    for (int i = 1; i <= n; i++)
        if (vis[i] == 0)
            return oo;
        else
            res += val[i];
    return res;
}

void solve()
{
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        int k; cin >> k;
        for (int j = 0; j < k; j++)
        {
            int x; cin >> x;
            leaders[i].push_back(x);
        }
    }

    ll res = oo;
    for (int i = 1; i <= n; i++)
        res = min(res, compute(i));

    cout << res << '\n';
}

Compilation message (stderr)

bosses.cpp: In function 'int main()':
bosses.cpp:19:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         freopen((name + ".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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