# Convert the array such that the GCD of the array becomes 1 in C++

In this tutorial, we will be discussing a program to convert the array such that the GCD of the array becomes one.

For this we will be provided with an array and a positive integer k. Our task is to convert the array elements such that the GCD of elements is 1 while only dividing the array elements by k any number of times until the element is less than k.

## Example

Live Demo

#include <bits/stdc++.h>
using namespace std;
//calculating the GCD of array
int calculate_gcd(int* arr, int n){
int gcd = arr[0];
for (int i = 1; i < n; i++)
gcd = __gcd(arr[i], gcd);
return gcd;
}
//checking if the operation is possible
bool convertGcd(int* arr, int n, int k){
int gcd = calculate_gcd(arr, n);
int max_prime = 1;
for (int i = 2; i <= sqrt(gcd); i++) {
while (gcd % i == 0) {
gcd /= i;
max_prime = max(max_prime, i);
}
}
max_prime = max(max_prime, gcd);
return (max_prime <= k);
}
int main(){
int arr[] = { 10, 15, 30 };
int k = 6;
int n = sizeof(arr) / sizeof(arr[0]);
if (convertGcd(arr, n, k) == true)
cout << "Yes";
else
cout << "No";
return 0;
}

## Output

Yes