Submission #993497

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Source Code Expand

#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <algorithm>
#include <sstream>
#include <cmath>
#include <set>
#include <iomanip>
#include <deque>
#include <stdio.h>
using namespace std;

#define REP(i,n) for(int (i)=0;(i)<(int)(n);(i)++)
#define RREP(i,n) for(int (i)=(int)(n)-1;i>=0;i--)
#define iREP(i,Itr) for(auto (i)=(Itr).begin();(i)!=(Itr).end();(i)++)
#define REMOVE(Itr,n) (Itr).erase(remove((Itr).begin(),(Itr).end(),n),(Itr).end())
#define PB_VEC(Itr1,Itr2) (Itr1).insert((Itr1).end(),(Itr2).begin(),(Itr2).end())
#define UNIQUE(Itr) sort((Itr).begin(),(Itr).end()); (Itr).erase(unique((Itr).begin(),(Itr).end()),(Itr).end())
#define LBOUND(Itr,val) lower_bound((Itr).begin(),(Itr).end(),(val))
#define UBOUND(Itr,val) upper_bound((Itr).begin(),(Itr).end(),(val))
typedef long long ll;

class UnionFindFixed{
    vector<int> data;
public:
    UnionFindFixed(int size) : data(size, -1) { }
    bool unionSet(int x, int y) {
        x = root(x); y = root(y);
        if (x != y) {
            if (data[y] < data[x]) swap(x, y);
            data[x] += data[y]; data[y] = x;
        }
        return x != y;
    }
    bool findSet(int x, int y) {
        return root(x) == root(y);
    }
    int root(int x) {
        return data[x] < 0 ? x : data[x] = root(data[x]);
    }
    int size(int x) {
        return -data[root(x)];
    }
};

int main(){
    
    int N,M; cin>>N>>M;
    vector<vector<int>> L;
    REP(i,N){
        vector<int> t;
        int K; cin>>K;
        REP(j,K){
            int tt; cin>>tt;
            t.push_back(tt);
        }
        L.push_back(t);
    }
    
    UnionFindFixed inst(300010);
    
    REP(i,N){
        REP(j,L[i].size()){
            inst.unionSet(i,L[i][j]+200000);
        }
    }
    
    int root=inst.root(0);
    REP(i,N){
        if(inst.root(i)!=root){
            cout<<"NO"<<endl;
            return 0;
        }
    }
    
    cout<<"YES"<<endl;
    
    return 0;
}

Submission Info

Judge Result