count-divisible.cpp

// CPP program to count divisible pairs. 
#include <iostream> 
using namespace std; 
  
int countDivisibles(int arr[], int n) 
{ 
    int res = 0; 
  
    // Iterate through all pairs 
    for (int i=0; i<n; i++)  
      for (int j=i+1; j<n; j++)  
            
         // Increment count if one divides 
         // other 
         if (arr[i] % arr[j] == 0 ||  
             arr[j] % arr[i] == 0)  
               res++; 
  
    return res; 
} 
  
int main() 
{ 
    int a[] = {1, 2, 3, 9}; 
    int n = sizeof(a) / sizeof(a[0]); 
    cout << countDivisibles(a, n); 
    return 0; 
}