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 9.2.1) (judge verdict: Wrong Answer)


#include <bits/stdc++.h>
#include <string.h>
#include <vector>
//s#define rep(i, n) for (int i = 0; i < (n); i++)
#define MAX 10000

using namespace std;

#define ll long long
#define pb push_back
#define mp make_pair
#define all(a) (a).begin(),(a).end()
#define rep(i,a,n) for(int i=a; i<n; i++)
#define r0 return 0
#define INF (int)1e15
#define MOD 1000000007

 int main(){

  int n; cin>>n;
  set<int>s;

  for(int i=0;i<n;i++)
 {
     int a;
     cin>>a;
     if(s.count(a)){
        cout<<"No"<<endl;
        return 0;
        }
      s.insert(a);
}

return 0;
}