Submission #3669863

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Source Code Expand

#include<stdio.h>
#include<stdlib.h>

int root(int *u,int x){
  if(u[x]==x) return x;
  return u[x]=root(u,u[x]);
}

int same(int *u,int x,int y){
  return root(u,x)==root(u,y);
}

void unite(int *u,int x,int y){
  x=root(u,x);
  y=root(u,y);
  if(x==y) return;
  u[x]=y;
}

void run(void){
  int n,m;
  scanf("%d%d",&n,&m);
  int *u=(int *)calloc(n+1,sizeof(int));
  int i;
  for(i=1;i<=n;i++) u[i]=i;
  int *d=(int *)calloc(m+1,sizeof(int));
  for(i=1;i<=n;i++){
    int k;
    scanf("%d",&k);
    while(k--){
      int l;
      scanf("%d",&l);
      if(d[l]==0){
	d[l]=i;
      } else {
	unite(u,d[l],i);
      }
    }
  }
  for(i=1;i<=n;i++) if(!same(u,1,i)) break;
  printf("%s\n",i>n?"YES":"NO");
}

int main(void){
  run();
  return 0;
}

Submission Info

Compile Error

./Main.c: In function ‘run’:
./Main.c:22:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&n,&m);
   ^
./Main.c:29:5: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&k);
     ^
./Main.c:32:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
       scanf("%d",&l);
       ^

Judge Result