Submission #991773

#	Time	Username	Problem	Language	Result	Execution time	Memory
991773		simona1230	Bitaro’s Party (JOI18_bitaro)	C++17	0 / 100	1 ms	3420 KiB

bitaro

#include <bits/stdc++.h>

using namespace std;

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

int n,m,q;
vector<int> v[100001];

void read()
{
    cin>>n>>m>>q;
    for(int i=1; i<=m; i++)
    {
        int x,y;
        cin>>x>>y;
        v[x].push_back(y);
    }
}

int dp[100001];
int vert,idx,ans;
int used[100001];

void dfs(int i)
{
    //cout<<i<<endl;
    if(i==vert)
    {
        if(used[i]!=idx)
            ans=0;
        dp[i]=0;
        return;
    }

    for(int j=0; j<v[i].size(); j++)
    {
        int nb=v[i][j];
        if(vert<nb)continue;

        if(dp[nb]==-1)
            dfs(nb);

        if(dp[nb]!=-1)
            dp[i]=max(dp[i],dp[nb]+1);
    }

    if(used[i]!=idx)
        ans=max(ans,dp[i]);
}

void solve()
{
    for(int i=1; i<=q; i++)
    {
        for(int j=1; j<=n; j++)
            dp[j]=-1;

        idx=i;
        int k,b;
        cin>>vert>>k;
        for(int j=1; j<=k; j++)
        {
            cin>>b;
            used[b]=i;
        }

        ans=-1;
        dfs(1);

        cout<<ans<<endl;
    }
}

int main()
{
    speed();
    read();
    solve();
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'void dfs(int)':
bitaro.cpp:41:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |     for(int j=0; j<v[i].size(); j++)
      |                  ~^~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86