Submission #1060574

#	Time	Username	Problem	Language	Result	Execution time	Memory
1060574		Szymon_Pilipczuk	The Xana coup (BOI21_xanadu)	C++17	5 / 100	1058 ms	7792 KiB

xanadu

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
    int n;
    cin>>n;
    int o[n];
    int ans = n+1;

    vector<int> tr[n];
    int a,b;
    for(int i = 0;i<n-1;i++)
    {
        cin>>a>>b;
        a--;b--;
        tr[a].push_back(b);
        tr[b].push_back(a);
    }
    for(int i =0;i<n;i++)
    {
        cin>>o[i];
    }
    for(int i = 0;i<(1<<n);i++)
    {
        int oc[n];
        copy(o,o+n,oc);
        int ci = i;
        int q = 0;
        int counter = 0;
        while(ci>0)
        {
            if(ci%2 == 1)
            {
                counter++;
                oc[q] = (oc[q]+1)%2;
                for(int j = 0;j<size(tr[q]);j++)
                {
                    oc[tr[q][j]]= (oc[tr[q][j]]+1)%2;
                }
            }
            q++;
            ci/=2;
        }
        bool win = true;
        for(int j = 0;j<n;j++)
        {
            if(oc[j] == 1)
            {
                win = false;
            }
        }
        if(i == 29)
        {
        }
        if(win)
        {
            ans = min(ans,counter);
        }

    }
    if (ans == n+1)
    {
        cout<<"impossible";
    }
    else
    {
        cout<<ans;
    }

}

Compilation message (stderr)

xanadu.cpp: In function 'int main()':
xanadu.cpp:38:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |                 for(int j = 0;j<size(tr[q]);j++)
      |                               ~^~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 40
• Subtask 5: 0 / 30