/*
 * factor.c
 * Chapter7
 * By John Stile
 * Purpose:
 * Write a program called factor.c that produces the produces
 *  the following factor output for a series of numbers using
 *  nested for loops.
 *
 *  1!= 1=1
 *  2!= 2*1 = 2
 *  3!= 3*2*1 = 6
 *  ...
 *  10!= 10*9*8*7*6*5*4*3*2*1 = 3628800
 */
#include <stdio.h>  // include stdio.h functions when compiling
#define NUM 10  // define a macro, where NUM will be reaplced by 10
int main(void)  // header for function main
{
  int xx,yy ;  // declare 2 intigers 
  float factorial; // declare a float

  for ( xx=1; xx<=NUM; xx=(xx+1) ) // outer loop, count from 1 to 10
  {
    factorial=1; // zero out factorial 
    printf("%d!=\t",xx);  // first part of output, current number
    for (yy=xx; yy>0; yy=(yy-1) ) // cycle through 1 to current xx
    {
      printf("%d*", yy);  // print each yy with a * after the digit
      factorial=(factorial*yy);  // calcuate the factoria by adding another mutilplyer each iteration
    }
    printf("\b"); // print the backspace, this removes the * from the final yy for this iteration.
    printf(" = %.0f\n", factorial);  // print the final result 
  }

  return 0;  // return 0 to calling function
}