Detective Debut

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

int n;
int arr[101010];

int main()
{
    cin >> n;
    int x;
    for (int i = 0; i < n; i++) {
        cin >> x;
        arr[x]++;
    }

    if (n == 1) {
        cout << "YES";
        return 0;
    }

    for (int i = 1; i <= n; i++) {
        if (i > 1 && arr[i] == 1) {
            cout << "YES";
            return 0;
        }
        if (arr[i] == i+2) {
            cout << "NO";
            return 0;
        }
    }

    if (arr[0] > 1) {
        cout << "NO";
        return 0;
    }
    if (n == 2) {
        if (arr[1] == 2 || (arr[1] == 1 && arr[0] == 1)) {
            cout << "NO";
            return 0;
        }
    }
    cout << "YES";
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED