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 JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

function Main(input) {
  input=input.split("\n");
  if(input[input.length-1]===''){
    input.pop();
  }
  const N=input[0];
  const array=input[1].split(' ').map(e=>{
    return e-0;
  });
  var memo=[];
  var message='YES';
  array.forEach(e=>{
    for(var i=0;i<memo.length;i++){
      if(memo[i]===e){
        message='NO';
        break;
      }else if(memo[i]>e){
        memo.splice(i,0,e);
        break;
      }
      if(i===memo.length-1){
        memo.push(e);
      }
    }
    if(memo.length===0){
      memo=[e];
    }
  });
  console.log(message);
        

}


//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));