/*
   This is a very simple program that accepts two arguments and returns the first raised to the second.

   To compile: gcc -o 02-power 02-power.c -Wall
   To run: ./02-power <number> <power>

   C. Andrews
   2015-02-17
*/


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

/*
  Computes x raised to y using a for loop.
*/
int power1(int x, int y){
  int result = 1;
  for (int i = 0; i < y; i++){
    result = result * x;
  }
  return result;
}

/*
  Computes x raised to y using a while loop.
*/
int power2(int x, int y){
  int result = 1;
  while (y > 0){
    result = result * x;
    y--;
  }
  return result;
}


/*
  Prints out all of the command line arguments, then returns the result of calling
  the two power functions on the input.
  */
int main(int argc, char * argv[]){
  // iterate over all of the arguments and print them out
  for (int i =0; i < argc; i++){
    // note the substitution characters %d - integer, %s - string
    printf("%d: %s\n",i, argv[i]);
  }

  int x, y;

  // convert the input strings to integers
  // atoi is a function found in stdlib
  x = atoi(argv[1]);
  y = atoi(argv[2]);

  printf("%d**%d = %d\n",x, y, power1(x,y));
  printf("%d**%d = %d\n",x, y, power2(x,y));



return 0;
}