fprime.c

// Assignment name  : fprime
// Expected files   : fprime.c
// Allowed functions: printf, atoi
// --------------------------------------------------------------------------------

// Write a program that takes a positive int and displays its prime factors on the
// standard output, followed by a newline.

// Factors must be displayed in ascending order and separated by '*', so that
// the expression in the output gives the right result.

// If the number of parameters is not 1, simply display a newline.

// The input, when there is one, will be valid.

// Examples:

// $> ./fprime 225225 | cat -e
// 3*3*5*5*7*11*13$
// $> ./fprime 8333325 | cat -e
// 3*3*5*5*7*11*13*37$
// $> ./fprime 9539 | cat -e
// 9539$
// $> ./fprime 804577 | cat -e
// 804577$
// $> ./fprime 42 | cat -e
// 2*3*7$
// $> ./fprime 1 | cat -e
// 1$
// $> ./fprime | cat -e
// $
// $> ./fprime 42 21 | cat -e
// $

#include <stdio.h>
#include <stdlib.h>

void fprime(int  n)
{
	int div = 1;

	if (n == 0)
		return ;
	if (n == 1)
		printf("1");
	while (n > div)
	{
		div++;
		if (n % div == 0)
		{
			printf ("%d", div);
			if (div == n)
				break ;
			printf ("*");
			n = n / div;
			div = 1;
		}
	}
}


int main(int ac, char **av)
{
	int n = atoi(av[1]);

	if (ac == 2)
	{
		fprime(n);
	}
	printf("\n");
	return (0);
}