Write a C Program to Find LCM of Number using Recursion

Recursion : :

• Recursion is the process of repeating items in a self-similar way. In programming languages, if a program allows you to call a function inside the same function, then it is called a recursive call of the function.

• The C programming language supports recursion, i.e., a function to call itself. But while using recursion, programmers need to be careful to define an exit condition from the function, otherwise it will go into an infinite loop.

• Recursive functions are very useful to solve many mathematical problems, such as calculating the factorial of a number, generating Fibonacci series, etc.

Problem : :

The following C program, using recursion, finds the LCM. An LCM is the lowest common multiple of any 2 numbers.

Below is the source code for C Program to Find LCM of Number using Recursion which is successfully compiled and run on Windows System to produce desired output as shown below :

SOURCE CODE : :

/* C Program to Find LCM of Number using Recursion */


#include <stdio.h>
 
int lcm(int, int);
 
int main()
{
    int a, b, result;
    int prime[100];
 
    printf("Enter two numbers: ");
    scanf("%d%d", &a, &b);
    result = lcm(a, b);
    printf("The LCM of %d and %d is %d\n", a, b, result);
    return 0;
}
 
int lcm(int a, int b)
{ 
    static int common = 1;
 
    if (common % a == 0 && common % b == 0)
    {
        return common;
    }
    common++;
    lcm(a, b);
    return common;
}

Output : :

***************** OUTPUT ********************


***************** FIRST RUN *****************

Enter two numbers:
14
6
The LCM of 14 and 6 is 42


***************** SECOND RUN *****************

Enter two numbers:
42
96
The LCM of 42 and 96 is 672