Submission #389202

#	Time	Username	Problem	Language	Result	Execution time	Memory
389202		AmineWeslati	Parachute rings (IOI12_rings)	C++14	0 / 100	8 ms	10036 KiB

rings

//Never stop trying
#include "bits/stdc++.h"
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

typedef long long ll;
typedef string str;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)

const int MOD = 1e9 + 7; //998244353
const ll INF = 1e18;
const int MX = 2e5 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up

template<class T> using V = vector<T>;
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
//constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
ll random(ll a, ll b){
    return a + rng() % (b - a + 1);
}
#ifndef LOCAL  
#define cerr if(false) cerr
#endif
#define dbg(x) cerr << #x << " : " << x << endl; 
#define dbgs(x,y) cerr << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << #v << " : " << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;
#define here() cerr << "here" << endl;

void IO() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin); 
    freopen("output.txt", "w", stdout);
#endif
}
/////////////////////////ONLY CLEAN CODES ALLOWED/////////////////////////


int N; 
vi adj[MX];

void Init(int N){
	::N=N; 
}

void Link(int u, int v){
	adj[u].pb(v); 
	adj[v].pb(u);
}

bool check(int x){
	vi adj2[N];
	FOR(i,0,N) if(i!=x){
		int cnt=0;
		for(auto u: adj[i]) if(u!=x){
			cnt++;
			adj2[i].pb(u);
		}
		if(cnt>2) return 0;
	}

	vi vis(N,0);
	FOR(i,0,N) if(i!=x && !vis[i]){
		int u=i; 
		while(1){
			vis[u]=1;

			int nxt=-1;
			for(auto v: adj2[u]) if(!vis[v]){
				nxt=v; 
			}
			if(nxt==-1 && sz(adj[u])==2) return 0;
			if(nxt==-1) break;
			u=nxt; 
		}

		vis[u]=0;
		u=i; 
		while(1){
			vis[u]=1;

			int nxt=-1;
			for(auto v: adj2[u]) if(!vis[v]){
				nxt=v; 
			}
			if(nxt==-1 && sz(adj[u])==2) return 0;
			if(nxt==-1) break;
			u=nxt; 
		}
	}
	

	return 1;
}

int CountCritical(){
	if(N==1) return 1;

	int ans=0;
	FOR(i,0,N) if(check(i)) ans++;
	return ans; 
}

#ifdef LOCAL
int main() {
    boost; IO();

    int N; cin>>N;
    Init(N);
    
    int Q; cin>>Q;
    while(Q--){
    	int t; cin>>t;
    	if(!t){
    		int u,v; cin>>u>>v;
    		Link(u,v);
    	}
    	else cout << CountCritical() << endl;
    }

    return 0;
}
#endif
//Change your approach 

• Subtask 1: 0 / 20
• Subtask 2: 0 / 17
• Subtask 3: 0 / 18
• Subtask 4: 0 / 14
• Subtask 5: 0 / 31