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 bubble(int a[], int na);
void tracer(int a[], int na);

int main()
{
    int i, na;
    int *a;
    
    printf("\n");
    if(scanf("%d", &na)==1)
    {
    a= calloc(na, sizeof(int));
  
        for(i=1; i<na+1; i++)
        {
            printf("\n");
            scanf("%d", &a[i]);
        }
        bubble(a, na);
        
    }
}
void bubble(int a[], int na)
{
    int i, j, temp;
    for(i=0; i<na-1; i++)
    {
        for (j=na-1; j>1; j--) {
            if(a[j-1]>a[j])
            {
                temp= a[j-1];
                a[j-1]= a[j];
                a[j]= temp;
            }
            
        }
    }
    tracer(a, na);
    
}
void tracer(int a[], int na){
    int i;
      
      for(i = 1 ; i < na+1 ; i ++) {
           printf("%d->[%d]", i ,a[i]);
      }
      
      if(a[i]==a[i+1])
      {
          printf("NO");
      }
      else
      {
          printf("YES");
      }
  }