Submission #570500

#	Time	Username	Problem	Language	Result	Execution time	Memory
570500		Huy	Bosses (BOI16_bosses)	C++17	67 / 100	1583 ms	980 KiB

bosses

#include<bits/stdc++.h>
//#define int long long
#define pii pair<int,int>
#define fi first
#define se second

using namespace std;
using ll = long long;
using ldb = long double;
const int N = (int)1e8;
const int maxN = (int)3e5 + 1;
const int mod = 1e9 + 7;

void InputFile()
{
    //freopen("scrivener.inp","r",stdin);
    //freopen("scrivener.out","w",stdout);
    //freopen("test.out","r",stdin);
}

void FastInput()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int n;
vector<vector<int>> adj1;
vector<int> adj2[5005];
int res = mod;
int check = 0;

void Read()
{
    cin >> n;
    adj1.resize(n+1);
    for(int i = 1;i <= n;i++)
    {
        int k;
        cin >> k;
        for(int j = 1;j <= k;j++)
        {
            int t;
            cin >> t;
            adj1[t].push_back(i);
        }

    }
}

int dp[maxN];
int trace[maxN];
int isvis[maxN];
int su[maxN];

void Trace(int v)
{
    isvis[v] = 1;
    int u = trace[v];
    if(u == 0) return;
    adj2[u].push_back(v);
    if(!isvis[u]) Trace(u);
}

void DFS(int u)
{
    su[u] = 1;
    for(int v : adj2[u])
    {
        DFS(v);
        su[u] += su[v];
    }
    check += su[u];
}

void BFS(int sta)
{
    for(int i = 1;i <= n;i++)
    {
        dp[i] = mod;
        isvis[i] = 0;
        trace[i] = 0;
        adj2[i].clear();
    }
    dp[sta] = 0;
    queue<int> q;
    q.push(sta);

    do
    {
        int u = q.front();
        q.pop();
        for(int v : adj1[u])
        {
            if(dp[v] > dp[u] + 1)
            {
                dp[v] = dp[u] + 1;
                trace[v] = u;
                q.push(v);
            }
        }
    }
    while(!q.empty());

    for(int i = 1;i <= n;i++)
    {
        if(dp[i] >= mod) return;
        if(!isvis[i]) Trace(i);
    }

    check = 0;
    DFS(sta);
    res = min(res,check);
}

void Solve()
{
    for(int i = 1;i <= n;i++)
        BFS(i);
    cout << res;
}

void Debug()
{
    //Main_sub();
    //Naive();
}


int32_t main()
{
    FastInput();
    //InputFile();
    //int sub_type;
    //cin >> sub_type;
    //Sieve();
    int test;
    //cin >> test;
    test = 1;
    while(test--)
        //for(int prc = 1; prc <= test; prc++)
    {
        Read();
        Solve();
        //Debug();
    }
}

/*
4 1
1 1 1 1
1 2
2 3
3 4
*/

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