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: Wrong Answer)

#include<stdio.h>
#include<stdlib.h>

void print(array, size)
long long* array;
{
	for (int i = 0; i < size; i++) {
		printf("%lld ", array[i]);
	}
	printf("\n");
}

void sort(array, size)
long long* array;
{
	for (int i = 0; i < size; i++) {
		for (int j = 0; j < size-i-1; j++) {
			if (array[j] > array[j + 1]) {
				int temp = array[j];
				array[j] = array[j + 1];
				array[j + 1] = temp;
			}
			print(array, size);
		}
	}
}

main(void) {
	unsigned N = 0;
	scanf("%u", &N);
	long long* llarray = malloc(sizeof(long long) * N);
	for (int i = 0; i < N; i++) {
		scanf("%lld", &llarray[i]);
	}
	sort(llarray, N);
	for (int i = 0; i < N; i++) {
		if (llarray[i] == llarray[i + 1]) {
			printf("No");
			return 0;
		}
	}
	printf("Yes");
	return 0;
}