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C program to find GCD (HCF) of two numbers using recursion
/* C program to find GCD (HCF) of two numbers using recursion
Write a recursive function in C to find GCD (HCF) of two numbers. How to find GCD(Greatest Common Divisor) or HCF(Highest Common Factor) of two numbers using recursion in C program.
Here in this program we will be using recursive approach of Euclidean algorithm to find GCD of two numbers. The Euclidean algorithm to find GCD is, */
Algorithm to find GCD using Euclidean algorithm
Begin:
function gcd(a, b)
If (b = 0) then
return a
End if
Else
return gcd(b, a mod b);
End if
End function
End
#include <stdio.h>
/* Function declaration */
int gcd(int a, int b);
int main()
{
int number1, number2, hcf;
/* Input two numbers from user */
printf("Enter any two numbers to find GCD: ");
scanf("%d%d", &number1, &number2);
hcf = gcd(number1, number2);
printf("GCD of %d and %d = %d", number1, number2, hcf);
return 0;
}
/* Recursive approach of euclidean algorithm to find GCD of two numbers */
int gcd(int a, int b)
{
if(b == 0)
return a;
else
return gcd(b, a%b);
}
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The if-else statement is used to perform two operations for a single condition. The if-else statement is an extension to the if statement using which, we can perform two different operations, i.e., one is for the correctness of that condition, and the other is for the incorrectness of the condition. Here, we must notice that if and else block cannot be executed simiulteneously. Using if-else statement is always preferable since it always invokes an otherwise case with every if condition.
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