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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;

public class Main
{
	public static void main(String args[])
	{
		int a;
		Scanner sc=new Scanner(System.in);
		a=sc.nextInt();
		int c=0;
		int b[]=new int[a];
		for(int i=0;i<a;i++)
		{
			b[i]=sc.nextInt();
		}
		Arrays.sort(b);
		for(int j=0;j<a-1;j++)
		{
			if(b[j]==b[j+1])
			{ c=c+1; }
		}
		if(c>0)
		{System.out.print("No");}
		else
		{System.out.print("Yes");}
	
	}
}