Input:

The first input line has an integer n: the number of values.

The second line has n integers x1,x2,…,xn.

Output:

Print one integers: the number of distinct values.
Constraints :

1≤n≤2⋅105
1≤xi≤109

Example:

Input:

5
2 3 2 2 3

Output:

2

Array based Solution

#include < iostream>
using namespace std;
int countDistinct(int arr[], int n){
    int res = 1;
    // Pick all elements one by one
    for (int i = 1; i < n; i++) {
        int j = 0;
        for (j = 0; j < i; j++){
            if (arr[i] == arr[j]){
                break;
             }
        // If not counted  earlier, then count it
        if (i == j){
            res++;
         }
    }
    return res;
}
 
int main(){

    int arr[] = { 12, 10, 9, 45, 2, 10, 10, 45 };
    int n = sizeof(arr) / sizeof(arr[0]);
    cout << countDistinct(arr, n);
    return 0;
}

Using vectors

#include < iostream>
#include< vector>

using namespace std;

int main(){

    int arr[] = { 12, 10, 9, 45, 2, 10, 10, 45 };
    int n = sizeof(arr) / sizeof(arr[0]); 
    
     vector nums(begin(arr), end(arr));
    
     sort(nums.begin(),nums.end());
      
    int dv=nums[0] ;
      int dn=1;
      for (int i = 1; i < nums.size(); i++) {
          if (dv !=nums[i]) {
             dn++;
             dv=nums[i] ;
             cout << nums[i] << endl;
           } 
      
      }     
 
    return 0;
}