Submission #1678136

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Source Code Expand

//------------------------------>> tsukasa_diary's template <<------------------------------//
#include <bits/stdc++.h>
using namespace std;

#define for_(i,a,b) for(int i=(a);i<(b);++i)
#define for_rev(i,a,b) for(int i=(a);i>=(b);--i)
#define allof(a) (a).begin(),(a).end()
#define minit(a,b) memset(a,b,sizeof(a))

using lint = long long;
using pii = pair< int, int >;

template< typename T > using Vec = vector< T >;

template< typename T > bool in_range(T x, T lb, T ub) { return lb <= x && x < ub; }
template< typename T > bool in_range(T x, T y, T lb, T ub) { return in_range(x, lb, ub) && in_range(y, lb, ub); }

template< typename T > void modAdd(T& a, T b, T mod) { a = (a + b + mod) % mod; }
template< typename T > void modMul(T& a, T b, T mod) { a = (a * b) % mod; }
template< typename T > void minUpdate(T& a, T b) { a = min(a, b); }
template< typename T > void maxUpdate(T& a, T b) { a = max(a, b); }

int bitCount(int x) { return __builtin_popcount(x); }
int bitCount(lint x) { return __builtin_popcountll(x); }

const int dx[4] = {0,1,0,-1}, dy[4] = {-1,0,1,0};
const int Dx[8] = {0,1,1,1,0,-1,-1,-1}, Dy[8] = {-1,-1,0,1,1,1,0,-1};
const double EPS = 1e-9;
const double PI = acos(-1);

//--------------8---------------->> coding space <<-----------------8-------------//

int N, M;
Vec< Vec< int > > adj;
Vec< bool > vis;

void dfs(int v) {
	if (vis[v]) return;
	vis[v] = true;
	for (int u : adj[v]) dfs(u);
}

int main() {
	cin >> N >> M;
	adj.assign(N + M, Vec< int >());
	for_(i,0,N) {
		int K;
		cin >> K;
		for_(j,0,K) {
			int L;
			cin >> L;
			--L;
			adj[i].push_back(N+L);
			adj[N+L].push_back(i);
		}
	}
	
	vis.assign(N+M, false);
	dfs(0);
	
	for_(i,0,N) {
		if (!vis[i]) {
			puts("NO");
			return 0;
		}
	}
	puts("YES");
}
//--------------8---------------->> coding space <<-----------------8-------------//

Submission Info

Judge Result