Submission #992042

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
#define MAX 200005
int pa[MAX];
int ra[MAX];
void init(){
  for(int i=0;i<MAX;i++){
    pa[i]=i;
    ra[i]=0;
  }
}

int find(int x){
  if(pa[x]==x)return x;
  else return pa[x]=find(pa[x]);
}

void unite(int x,int y){
  x=find(x),y=find(y);
  if(x==y)return;
  if(ra[x]<ra[y])swap(x,y);
  pa[y]=x;
  if(ra[x]==ra[y])ra[x]++;
}

bool same(int x,int y){
  return (find(x)==find(y));
}

int N,M;
int K[MAX];
vector<int> G[MAX];

int main(){
  init();
  scanf("%d %d",&N,&M);
  for(int i=0;i<N;i++){
    scanf("%d",&K[i]);
    for(int j=0;j<K[i];j++){
      int id;
      scanf("%d",&id);
      id--;
      if(G[i].size() > 0)unite(G[i].back() , id);
      G[i].push_back(id);
      unite( i , N+id);
    }
  }
  
  int cnt=0;
  for(int i=0;i<N;i++){
    if(i==find(i))cnt++;
  }
  
  if(cnt==1){
    printf("YES\n");
  }else{
    printf("NO\n");
  }
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:36:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&N,&M);
                       ^
./Main.cpp:38:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&K[i]);
                      ^
./Main.cpp:41:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
       scanf("%d",&id);
                      ^

Judge Result