Submission #591566

#	Time	Username	Problem	Language	Result	Execution time	Memory
591566		andrei_boaca	Potemkin cycle (CEOI15_indcyc)	C++14	60 / 100	939 ms	2036 KiB

indcyc

#include <bits/stdc++.h>
#pragma GCC optimize("O3")

using namespace std;
mt19937 rng(time(NULL));
vector<int> muchii[1005];
auto S=chrono::steady_clock::now();
int n,m;
vector<int> v;
bool use[1005];
int start=0;
void dfs(int nod)
{
    auto E=chrono::steady_clock::now();
    int x=chrono::duration_cast<chrono::milliseconds>(E - S).count();
    if(x>=950)
    {
        cout<<"no";
        exit(0);
    }
    use[nod]=1;
    bool good=1;
    bool ok=0;
    if(nod==4)
    {
        /*for(int i:v)
            cout<<i<<' ';*/
        ok=1;
    }
    for(int i:muchii[nod])
    {
        if(use[i])
        {
            if(i==v[v.size()-2])
                continue;
            if(i==start)
            {
                if(v.size()>=4)
                    continue;
                else
                {
                    good=0;
                    break;
                }
            }
            else if(i!=v[v.size()-2])
            {
                good=0;
                break;
            }
        }
    }
    if(good)
    {
        for(int i:muchii[nod])
            if(i==start&&v.size()>=4)
            {
                for(int j:v)
                    cout<<j<<' ';
                exit(0);
            }
        for(int i:muchii[nod])
            if(!use[i])
            {
                v.push_back(i);
                use[i]=1;
                dfs(i);
                use[i]=0;
                v.pop_back();
            }
    }
}
int main()
{
    cin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int a,b;
        cin>>a>>b;
        muchii[a].push_back(b);
        muchii[b].push_back(a);
    }
    vector<int> nodes;
    for(int i=1;i<=n;i++)
        nodes.push_back(i);
    shuffle(nodes.begin(),nodes.end(),rng);
    for(int i:nodes)
    {
        start=i;
        v.clear();
        v.push_back(i);
        for(int j=1;j<=n;j++)
            use[j]=0;
        dfs(i);
    }
    cout<<"no";
    return 0;
}

Compilation message (stderr)

indcyc.cpp: In function 'void dfs(int)':
indcyc.cpp:23:10: warning: variable 'ok' set but not used [-Wunused-but-set-variable]
   23 |     bool ok=0;
      |          ^~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 0 / 10
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10