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 (GCC 5.4.1) (judge verdict: Runtime Error)

#include<stdio.h>
int main()
{
	long long int num;
	long long int ar[20000] = { 0 };
	scanf("%lld", &num);
	long long int i = 1;
	int prime = 1;
	while (i <= num)
	{
		long long int temp;;
		scanf("%lld", &ar[i]);
		for (int j = 1; j < i; j++) {
			if (ar[j] == ar[i]) {
				prime = 0;
				break;
			}
		}
		if (prime == 0)break;
		i++;
	}
		if (prime == 1)printf("YES\n");
		else printf("NO\n");
	return 0;
}