Submission #857837

#	Time	Username	Problem	Language	Result	Execution time	Memory
857837		UmairAhmadMirza	Potemkin cycle (CEOI15_indcyc)	C++14	10 / 100	1 ms	348 KiB

indcyc

//In the name of Allah the most beneficent, the most merciful.
#include <bits/stdc++.h>

using namespace std;

// #pragma GCC optimize("Ofast,unroll-loops") 
// #pragma GCC target("avx,avx2,avx512,fma") 
#define int long long
#define ar array
#define ll long long
#define ld long double
#define sza(x) ((int)x.size())
#define all(a) (a).begin(), (a).end()

#define PI 3.1415926535897932384626433832795l 
const int N = 12;
const ll MOD = 1e9 + 7;
const ll INF = 1e9;
const ld EPS = 1e-9;

// -------------------------<RNG>------------------------- 
// RANDOM NUMBER GENERATOR
mt19937 RNG(chrono::steady_clock::now().time_since_epoch().count());  
#define SHUF(v) shuffle(all(v), RNG); 
// Use mt19937_64 for 64 bit random numbers.
//--------------------------------------------------------
//int defined as long long
map<pair<int,int>,int> mp;
vector<int> adj[N];
int n,m;
int mask=0;
int vis=0;
int ed[N];
vector<int> path;
void dfs(int node){
	vis|=(1<<node);
	path.push_back(node);
	for(auto i:adj[node])
		if( ((vis&(1<<i))==0) && (mask&(1<<i)))
			dfs(i);
}
bool check2(){
	int sz=path.size();
	if(sz<4)
		return 0;
	set<int> s;
	for(auto i:path)
		s.insert(i);
	int szz=s.size();
	if(szz!=sz)
		return 0;
	if(mp[{path[0],path[sz-1]}]==0)
		return 0;
	for(int i=0;i<sz-1;i++)
		if(mp[{path[i],path[i+1]}]==0)
			return 0;
	for(int i=0;i<sz;i++)
		for(int j=i+2;j<sz;j++)
			if(mp[{path[i],path[j]}]&&(i!=0||j!=sz-1)){
				cout<<i<<' '<<j<<endl;
				return 0;
			}
	return 1;
}
bool check(){
	for(int i=0;i<n;i++)
		ed[i]=0;
	for(int i=0;i<n;i++){
		if((mask&(1<<i))==0)
			continue;
		for(int j=i+1;j<n;j++){
			if((mask&(1<<j))==0)
				continue;
			ed[i]+=mp[{i,j}];
			ed[j]+=mp[{i,j}];
			
		}
	}
	for(int i=0;i<n;i++){
		if((mask&(1<<i)) && ed[i]!=2)
			return 0;
	}
	path.clear();
	vis=0;
	for(int i=0;i<n;i++)
		if(mask&(1<<i)){
			dfs(i);
			break;
		}	
	if(vis!=mask)
		return 0;
	if(check2()==0){
		while(1);
	}
	cout<<path.size()<<endl;
	for(auto i:path)
		cout<<i+1<<' ';
	cout<<endl;
	return 1;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    cin>>n>>m;
    if(n>10)
    	return 0;
    for(int i=0;i<m;i++){
    	int a,b;
    	cin>>a>>b;
    	a--;
    	b--;
    	mp[{a,b}]++;
    	mp[{b,a}]++;
    	adj[a].push_back(b);
    	adj[b].push_back(a);
    }
    while(mask<(1<<n)){
    	mask++;
    	if(__builtin_popcount(mask)<4)
    		continue;
    	if(check())
    		return 0;
    }
    cout<<"no"<<endl;
    return 0;
}

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