krx60410.c

answer of the c programming language second edition

/*

  Chapter 6. Structures

          Write a program that prints out the distinct words in its 
          input sorted into decreasing order of frequency of occurrence.
          Precede each word by its count.

  Author: Bryan Williams

*/

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

#include <assert.h>


typedef struct WORD
{
  char *Word;
  size_t Count;
  struct WORD *Left;
  struct WORD *Right;
} WORD;


/*
  Assumptions: input is on stdin, output to stdout.

  Plan: read the words into a tree, keeping a count of how many we have,
        allocate an array big enough to hold Treecount (WORD *)'s 
        walk the tree to populate the array.
        qsort the array, based on size.
        printf the array
        free the array
        free the tree
        free tibet (optional)
        free international shipping!
*/

#define SUCCESS                      0
#define CANNOT_MALLOC_WORDARRAY      1
#define NO_WORDS_ON_INPUT            2
#define NO_MEMORY_FOR_WORDNODE       3
#define NO_MEMORY_FOR_WORD           4


#define NONALPHA "1234567890 \v\f\n\t\r+=-*/\\,.;:'#~?<>|{}[]`!\"