Submission #991501

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Source Code Expand

#include<stdio.h>
#include<vector>
#include<algorithm>
using namespace std;
#define SIZE 200000
class unionfind
{
public:
	int par[SIZE];
	int ran[SIZE];
	int ren[SIZE];
	void init()
	{
		for(int i=0;i<SIZE;i++)
		{
			par[i]=i;
			ran[i]=0;
			ren[i]=1;
		}
	}
	int find(int a)
	{
		if(a==par[a])return a;
		else return par[a]=find(par[a]);
	}
	void unite(int a,int b)
	{
		a=find(a);
		b=find(b);
		if(a==b)return;
		if(ran[a]>ran[b])
		{
			par[b]=a;
			ren[a]+=ren[b];
		}
		else
		{
			par[a]=b;
			ren[b]+=ren[a];
		}
		if(ran[a]==ran[b])ran[b]++;
	}
};
unionfind uf;
int main()
{
	uf.init();
	int num,gen;
	scanf("%d%d",&num,&gen);
	for(int i=0;i<num;i++)
	{
		int z;
		scanf("%d",&z);
		for(int j=0;j<z;j++)
		{
			int a;
			scanf("%d",&a);
			a--;
			uf.unite(i,a+100000);
		}
	}
	int t=uf.find(0);
	for(int i=0;i<num;i++)
	{
		if(t!=uf.find(i))
		{
			printf("NO\n");
			return 0;
		}
	}
	printf("YES\n");
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:49:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&num,&gen);
                         ^
./Main.cpp:53:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&z);
                 ^
./Main.cpp:57:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&a);
                  ^

Judge Result