Submission #879246

#	Time	Username	Problem	Language	Result	Execution time	Memory
879246		vjudge1	Logičari (COCI21_logicari)	C++17	20 / 110	23 ms	2808 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5 + 10, MOD = 998244353;

bool is[N];
vector<int> g[N];
int check(int n){
    int res = 1e9;
    for(int i = 0;i < (1 << n);i++){
        for(int j = 0;j < n;j++){
            if((i >> j) & 1){
                is[j + 1] = 1;
            }else{
                is[j + 1] = 0;
            }
        }
        bool ok = true;
        for(int j = 1;j <= n;j++){
            int x = 0;
            for(int to:g[j]){
                x += is[to];
            }
            if(x != 1){
                ok = false;
                break;
            }
        }
        if(ok){
            res = min(res,__builtin_popcount(i));
        }
    }
    if(res == 1e9) res = -1;
    return res;
}
int n;
void solve(){
    for(int i = 1;i <= n;i++){
        int x,y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int res = check(n);
    if(res == -1){
        cout << res;
        return;
    }
    assert((n / 2) - res >= 0);
    cout << res;
}
void test(){
    cin >> n;
    if(n <= 20){
        solve();
        return;
    }
    if(n % 4){
        cout << -1;
        return;
    }
    cout << n / 2;
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int T = 1;
    // cin >> T;
    for(int i = 1;i <= T;i++)
    {
        test();
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 40
• Subtask 4: 0 / 50