Submission #861753

#	Time	Username	Problem	Language	Result	Execution time	Memory
861753		Ahmed_Solyman	Logičari (COCI21_logicari)	C++14	0 / 110	2 ms	604 KiB

Main

/*
In the name of Allah
made by: Ahmed_Solyman
*/
#include <bits/stdc++.h>
#include <ext/rope>
 
using namespace std;
using namespace __gnu_cxx;
#pragma GCC optimize("-Ofast")
#pragma GCC optimize("-O1")
//-------------------------------------------------------------//
typedef long long ll;
typedef unsigned long long ull;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define PI acos(-1)
#define lb lower_bound
#define ub upper_bound
#define endl '\n'
#define all(v) v.begin(),v.end()
#define allr(v) v.rbegin(),v.rend()
#define sum_to(n) (n*(n+1))/2
#define pb push_back
#define pf push_front
#define fil(arr,x) memset(arr,x,sizeof(arr))
const ll mod=1e9+7;
int dx[8]={0,1,0,-1,1,1,-1,-1};
int dy[8]={1,0,-1,0,1,-1,-1,1};
//-------------------------------------------------------------//
ll lcm(ll a,ll b)
{
    return (max(a,b)/__gcd(a,b))*min(a,b);
}
void person_bool(bool x)
{
    cout<<(x?"YES":"NO")<<endl;
}
int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    #ifndef ONLINE_JUDGE
    freopen("input.in", "r", stdin);
    freopen("output.out", "w", stdout);
    #endif
    fast
    int n;cin>>n;
    vector<int>adj[n];
    int deg[n];
    for(int i=0;i<n;i++){
    	int u,v;cin>>u>>v;u--;v--;
    	deg[u]++;deg[v]++;
    	adj[u].push_back(v);
    	adj[v].push_back(u);
    }
    bool ok=1;
    for(int i=0;i<n;i++)ok&=(deg[i]==2);
    if(ok){
    	if(n%4)cout<<-1<<endl;
    	else cout<<n/2<<endl;
    	return 0;
    }
    int ans=-1;
    for(int i=1;i<(1<<n);i++){
    	vector<bool>v(n);
    	for(int j=0;j<n;j++){
    		if((1<<j)&i){
    			v[j]=1;
    		}
    	}
    	bool valid=1;
    	for(int j=0;j<n;j++){
    		int cnt=0;
    		for(auto ch:adj[j]){
    			if(v[ch])cnt++;
    		}
    		valid&=(cnt==1);
    	}
    	if(valid){
    		if(ans==-1){
    			ans=__builtin_popcount(i);
    		}
    		else{
    			ans=min(ans,__builtin_popcount(i));
    		}
    	}
    }
    cout<<ans<<endl;
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     freopen("input.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:44:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |     freopen("output.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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