How to Find GCD using Function in C++, OOP

 Q :  Write a function for finding GCD of two integer number. Then input three integer number through keyboard in main program and call the GCD function, so that final GCD of three number should be evaluated and displayed.

Answer:::

#include <iostream>

using namespace std;

int greatest_num(int a, int b, int c)

{

if(a>=b && a>=c)

{

return a;

}

else if(b>=a && b>=c)

{

return b;

}

else if(c>=a && c>=b)

{

return c;

}

}

int main()

{

int m,n,o;

 cout<<"Enter three Numbers for Finding GCD : ";

 cin>>m>>n>>o;

int result;

for(result=greatest_num(m,n,o); result>=1; result--){

if(m%result==0 && n%result==0 && o%result==0){

break;

}

}

cout<<"GCD of the given numbers is : "<<result<<endl;

return 0;

}