C++ :

#include<bits/stdc++.h>
using namespace std;
int t,n,a[105];
int f(int x,int y)
{
	if(y-x>1) return 1;
	else return 0;
}
int main()
{
//	freopen("1.in","r",stdin);
//	freopen("1.out","w",stdout);
	cin>>t;
	while(t--)
	{
		fill(a,a+103,0);
		int bj=0;
		cin>>n;
		for(int i=1;i<=n;i++)
			cin>>a[i];
		sort(a+1,a+1+n);
		for(int i=2;i<=n;i++)
			if(f(a[i-1],a[i])==1) {bj=1;break;}
		if(bj==1) cout<<"NO"<<endl;
		else cout<<"YES"<<endl;
	}	
    return 0;
}