Problem:
Score : 300 points

Problem Statement

Given is a sequence of integers A_1, A_2, ..., A_N.
If its elements are pairwise distinct, print YES; otherwise, print NO.

Constraints

2 ≤ N ≤ 200000

1 ≤ A_i ≤ 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 ... A_N

Output

If the elements of the sequence are pairwise distinct, print YES; otherwise, print NO.

Sample Input 1

5
2 6 1 4 5

Sample Output 1

YES

The elements are pairwise distinct.

Sample Input 2

6
4 1 3 1 6 2

Sample Output 2

NO

The second and fourth elements are identical.

Sample Input 3

2
10000000 10000000

Sample Output 3

NO

Solution in C++14 (GCC 5.4.1) (judge verdict: Runtime Error)

#include<stdio.h>
int main()
{  
int n,s[100000],i,j,k,t,xxx=0;
scanf("%d",&n);
for(i=0;i<n;i++)
 scanf("%d",&s[i]);
 for(j=1;j<=i-1;j++)
  for(k=0;k<=i-j-1;k++)
  if(s[k]<s[k+1])
  {
	t=s[k];s[k]=s[k+1];s[k+1]=t;
  }
for(i=0;i<n;i++)
{
	if(s[i]==s[i+1])
		xxx=1;
}	 
 if(xxx==0)
	 printf("YES");
 else
	 printf("NO");
    return 0;
}