Submission #5017434

---

Source Code Expand

#include <bits/stdc++.h>
using namespace std;
int n,m;
int k,x,fa;
int f[100005];
int vis[100005];
int find(int x)
{
	if(x==f[x])
		return x;
	return f[x]=find(f[x]);
}
int main() {
	scanf("%d %d",&n,&m);
	for(int i=1;i<=m;i++)
	{
		f[i]=i;
	}
	while(n--)
	{
		scanf("%d",&k);
		scanf("%d",&x);
		fa=find(x);
		vis[x]=1;
		for(int i=1;i<k;i++)
		{
			scanf("%d",&x);
			vis[x]=1;
			f[find(x)]=fa;
		}
	}
	fa=find(x);
	for(int i=1;i<=m;i++)
	{
		if(vis[i]&&find(i)!=fa)
		{
			printf("NO\n");
			return 0;
		}
	}
	printf("YES\n");
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:14:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&m);
                      ^
./Main.cpp:21:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&k);
                 ^
./Main.cpp:22:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x);
                 ^
./Main.cpp:27:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&x);
                  ^

Judge Result