Submission #992045

---

Source Code Expand

#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <cassert>
#include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <set>
#include <map>
#include <bitset>
#include <functional>
using namespace std;

#define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define rep(i,n) repl(i,0,n)
#define mp(a,b) make_pair((a),(b))
#define pb(a) push_back((a))
#define all(x) (x).begin(),(x).end()
#define dbg(x) cout<<#x"="<<((x))<<endl
#define fi first
#define se second

#define INF 2147483600

class UnionFind {
public:
  vector<int> par, rank; // parent(negative := its root and abs-value is its size), depth
  UnionFind(int sz) : par(sz, -1), rank(sz, 0){}
  int find(int x){
    if(par[x]<0) return x;
    else return par[x] = find(par[x]);
  }
  void unite(int x, int y){
    x=find(x); y=find(y);
    if(x==y) return;  // already belong to same tree
    if(rank[x] < rank[y]){  // y becomes parent node
      par[y] += par[x];
      par[x] = y;
    } else {  // x becomes parent node
      par[x] += par[y];
      par[y] = x;
      if(rank[x]==rank[y]) rank[x]++;
    }
  }
  bool same(int x, int y){ return find(x) == find(y); }
  int size(int x){ return -par[find(x)]; }
}; // END class UnionFind


int main(){
  int n,m;
  cin>>n>>m;

  vector<vector<int> > lang2p(m, vector<int>());
  rep(i,n){
    int k;
    scanf("%d", &k);
    rep(j,k){
      int l;
      scanf("%d", &l);
      l--;
      lang2p[l].pb(i);
    }
  }

  UnionFind uf(n);
  rep(i,m) repl(j,1,lang2p[i].size()){
    uf.unite(lang2p[i][j], lang2p[i][0]);
  }

  if(uf.size(0)==n){
    cout<<"YES"<<endl;
  } else {
    cout<<"NO"<<endl;
  }

  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:60:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &k);
                    ^
./Main.cpp:63:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
       scanf("%d", &l);
                      ^

Judge Result