factor using recursion code example

Example 1: recursion factorial algorithm

FUNCTION FACTORIAL (N: INTEGER): INTEGER
(* RECURSIVE COMPUTATION OF N FACTORIAL *)

BEGIN
  (* TEST FOR STOPPING STATE *)
  IF N <= 0 THEN
    FACTORIAL := 1
  ELSE
    FACTORIAL := N * FACTORIAL(N - 1)
END; (* FACTORIAL *)

Example 2: factors using recursion

/* C Program to print prime factors*/
 
 
#include<stdio.h>
void PFactors( int num);
void IPFactors( int n);
 
int main( )
{
	int num;
	printf("Enter a number : ");
	scanf("%d", &num);
	printf("\nUsing Recursion :: \n");
	PFactors(num);
	printf("\n");
	printf("\nUsing Iteration :: \n");
	IPFactors(num);
	printf("\n");
 
	return 0;
 
}/*End of main()*/
 
/*Recursive*/
 
void PFactors( int num)
{
	int i = 2;
	if( num == 1 )
		return;
	while( num%i != 0 )
		i++;
	printf("%d ", i);
	PFactors(num/i);
}/*End of PFactors()*/
 
/*Iterative*/
void IPFactors( int num)
{
	int i;
	for( i = 2; num!=1; i++)
		while( num%i == 0 )
		{
			printf("%d ", i);
			num = num/i;
		}
}/*End of IPFactors()*/