/* ==================================================================
 *
 * CS 160, Fall 2005 (Beck
 *
 * ARM Lab 2 --- Word Parsing [SOLUTION]
 *
 * wordmain.c
 *
 * Driver program that populates lists to be manipulated/sorted by
 * three external ARM assembly routines (found in 'asmsort.s').
 *
 * ================================================================== */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

// Number of input bytes...
#define N 100

// Reference external ARM assembly routines...
extern void genwords(char *A, char **B);
extern int wordgt(char *A, char *B);
extern void sortwords(char **B);
int main (int argc, char *argv[]) {
  char *listS, **listR, **p;
  int i;
  
  // Allocate memory for two lists...
  listS = (char *) malloc(N * sizeof(char));
  listR = (char **) malloc(N * sizeof(char *));

  // Create input list
  strcpy(listS, "how much wood can a wood chuck canoodle ");

  // Call genwords...
  genwords(listS, listR);

  // Print the list of words
  for (p = listR; *p; p++)
    printf("%s\n", *p);
  printf("\n");

  // Call sortwords...
  sortwords(listR);

  // Print the list of words after sortwords
  for (p = listR; *p; p++)
    printf("%s\n", *p);
  printf("\n");

  // Free memory allocated for the lists...
  free(listS);
  free(listR);

  return 0;
}

void genwords(char *S, char **R)
{
  char *p = S;
  char **q = R;

  while (*p) {
    *(q++) = p;
    while (*p != ' ') p++;
    *p = 0;
    p++;
  }
  *q = 0;
}

int wordgt(char *A, char *B)
{
  char *pa = A;
  char *pb = B;

  while (*pa == *pb) {pa++; pb++;}
  if (*pa > *pb) return 1;
  else return 0;
}

void sortwords(char **list)
{
  int j, k;
  char *tmp;

  for (j=0; j<N && list[j]; j++) ;
  for (--j; j>0; j=j-1){
    for (k=j-1; k>=0; k=k-1) {
      if (wordgt(list[k], list[j])) {
	tmp = list[k];
	list[k] = list[j];
	list[j] = tmp;
      }
    }
  }
}