/*
 * 9b.c  | Jim M | Sep 2010
 * projecteuler.net #9, version b
 *
 * typedef, struct, malloc, and pointers.
 *
 *   All this infrastructure is overkill for this simple example,
 *   but this template works for much more complicated things.
 *   I encourage you to study this one, and keep to a similar style.
 *
 *   In fact, all the memory allocation & deallocation will
 *   will slow this down substantially ... but this is how you 
 *   create "object like" things in C and pass around pointers to them.
 * 
 */
#include <stdio.h>
#include <stdlib.h>

typedef struct _triple *triple;
struct _triple {
  int a;
  int b;
  int c;
};
triple new_triple(int a, int b, int c){
  // Allocate memory on the heap for this thing, and return a pointer to it.
  triple t = (triple) malloc(sizeof(struct _triple));
  t->a = a;
  t->b = b;
  t->c = c;
  return t;
}
void free_triple(triple t){
  free(t);  // In a more complex struct, we'd need to free the innards.
}
void print_triple(triple t){
  printf("a = %i, b = %i, c = %i \n", t->a, t->b, t->c);
}
int is_pythagorean(triple t){
  // Return true if this is a pythogrean triple.
  return (t->a)*(t->a) + (t->b)*(t->b) == (t->c)*(t->c);
}

int main(){
  int a, b, c;
  int sum = 1000;
  triple p;
  printf("Looking for triple such that a**2+b**2=c**2 and a+b+c=%i ...\n", sum);
  for (a = 1; a < sum-2; a++){
    for (b = a+1; b < sum-2; b++){
      c = sum - a - b;
      p = new_triple(a, b, c);
      if (is_pythagorean(p)){
        print_triple(p);
        return 0;
      }
    }
    free_triple(p);
  }
  printf("no solution found.\n");
  return 0;
}