﻿ C exercises: Find the LCM of two numbers - w3resource

# C Exercises: Find the LCM of two numbers

## C Recursion : Exercise-13 with Solution

Write a program in C to find the LCM of two numbers using recursion.

Sample Solution:

C Code:

``````#include <stdio.h>
int lcmCalculate(int a, int b);

int main()
{
int n1, n2, lcmOf;
printf("\n\n Recursion : Find the LCM of two numbers :\n");
printf("----------------------------------------------\n");
printf(" Input 1st number for LCM : ");
scanf("%d", &n1);
printf(" Input 2nd number for LCM : ");
scanf("%d", &n2);
// Ensures that first parameter of lcm must be smaller than 2nd
if(n1 >  n2)
lcmOf = lcmCalculate(n2, n1);//call the function lcmCalculate for lcm calculation
else
lcmOf = lcmCalculate(n1, n2);//call the function lcmCalculate for lcm calculation
printf(" The LCM of %d and %d :  %d\n\n", n1, n2, lcmOf);
return 0;
}
int lcmCalculate(int a, int b)//the value of n1 and n2 is passing through a and b
{
static int m = 0;
//Increments m by adding max value to it
m += b;
//  If found a common multiple then return the m.
if((m % a == 0) && (m % b == 0))
{
return m;
}
else
{
lcmCalculate(a, b);//calling the function lcmCalculate itself
}
}
```
```

Sample Output:

``` Recursion : Find the LCM of two numbers :
----------------------------------------------
Input 1st number for LCM : 4
Input 2nd number for LCM : 6
The LCM of 4 and 6 :  12
```

Flowchart:

C Programming Code Editor:

```#include <stdio.h>
int lcmCalculate(int a, int b);

int main()
{
int n1, n2, lcmOf;
printf("\n\n Recursion : Find the LCM of two numbers :\n");
printf("----------------------------------------------\n");
printf(" Input 1st number for LCM : ");
scanf("%d", &n1);
printf(" Input 2nd number for LCM : ");
scanf("%d", &n2);
// Ensures that first parameter of lcm must be smaller than 2nd
if(n1 >  n2)
lcmOf = lcmCalculate(n2, n1);//call the function lcmCalculate for lcm calculation
else
lcmOf = lcmCalculate(n1, n2);//call the function lcmCalculate for lcm calculation
printf(" The LCM of %d and %d :  %d\n\n", n1, n2, lcmOf);
return 0;
}
int lcmCalculate(int a, int b)//the value of n1 and n2 is passing through a and b
{
static int m = 0;
//Increments m by adding max value to it
m += b;
//  If found a common multiple then return the m.
if((m % a == 0) && (m % b == 0))
{
return m;
}
else
{
lcmCalculate(a, b);//calling the function lcmCalculate itself
}
}```

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