# C++ Program to Calculate GCD of Two Numbers

Here is a C++ program to calculate GCD and HCF of two numbers.

## C++ program to find GCD of two numbers

```#include <iostream>

using namespace std;

int getMinimum(int a, int b){
if(a >= b)
return b;
else
return a;
}

int main() {
int a, b, min, i, gcd = 1;
/*
* Take two numbers as input from user
*/
cout << "Enter Two Integers\n";
cin >> a >> b;

min = getMinimum(a, b);
// Search for larget number less than min which divides both a and b
for(i = 1; i <= min; i++) {
if(a%i==0 && b%i==0) {
/* Update GCD to new larger value */
gcd = i;
}
}

cout << "GCD of " << a << " and " << b << " is " << gcd;
return 0;
}
```
Output
```Enter Two Integers
30 12
GCD of 30 and 12 is 6
```

## C++ program to find GCD of two numbers by repetative subtracting

```#include <iostream>

using namespace std;

int main() {
int num1, num2;
cout << "Enter Two Integers\n";
cin >> num1 >> num2;

while(num1 != num2) {
if(num1 > num2)
num1 = num1 - num2;
else
num2 = num2 - num1;
}

cout << "GCD is " << num1;

return 0;
}
```
Output
```Enter Two Integers
22 8
GCD is 2
```

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