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 Rust (1.42.0) (judge verdict: Accepted)

use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {n: usize, b: [u64; n]};
    let mut b: Vec<u64> = b;

    if init_b_len(&b) == uniqe_b_len(&mut b) {
        println!("YES")
    } else {
        println!("NO")
    }
}

fn init_b_len(b: &Vec<u64>) -> usize {
    b.len()
}

fn uniqe_b_len(b: &mut Vec<u64>) -> usize {
    b.sort();
    b.dedup();
    b.len()
}