prog4.txt

别处下的一个huffman压缩程序

#include <stdio.h>
#include <stdlib.h>
#include "error.h"
#include "minheap.h"
#include "hufftree.h"
//prog4.c//

/* function prototypes */
HuffTree SortTree(MinHeap);
int * ReadCharacters(FILE *);

int main(void)
{
   int *char_array;
   MinHeap mh;
   HuffTree temp,ht;
   FILE *fp;
   int i;char name[15];
   /* open the text file */
   printf("Enter the file name:");
           scanf("%s",name);
   fp = fopen(name, "r");
	if(fp == NULL)
    FatalError("File not found not found!");
   }

   mh = NewMinHeap();

   /* read the data file, counting the number of times each char
      occurs in it */
   char_array = ReadCharacters(fp);

   /* finished with the file, so close it */
   fclose(fp);

   /* create a temporary HuffTree based upon the frequencies of the
      chars read from the file */
   for(i = 0; i < MAX_ARRAY; i++)
   {
      if(char_array[i] != 0)
      {
         temp = NewHuffTree(i,char_array[i]);
         InsertMinHeap(mh,temp);
      }
	}
   /* sorts the HuffTree for optimal size based upon frequencies */
   ht = SortTree(mh);

   /* output the resulting HuffTree codes to the screen */
   OutputHuffCodes(ht);
   return 1;
}

/* "sorts" the HuffTree so that characters are only in the leaves */
HuffTree SortTree(MinHeap mh)
{
   HuffTree q, p, new;

   while(SizeMinHeap(mh) > 1)
   {
      q = DeleteMinHeap(mh);
      p = DeleteMinHeap(mh);
      new = JoinHuffTrees(q,p);
      InsertMinHeap(mh, new);
   }

	new = DeleteMinHeap(mh);
   }

/* reads the characters from the text file, counting the number of times
   each character occurs */
int * ReadCharacters(FILE *fp)
{
   int *char_array, i, c;

   c = 1;

   char_array = malloc(MAX_ARRAY * sizeof(int));
   if(char_array == NULL)
   {
      FatalError("Not enough memory!");
   }

   for(i = 0; i < MAX_ARRAY; i++)
   {
      char_array[i] = 0;
   }

	while(c != EOF)
   c = 1;

   char_array = malloc(MAX_ARRAY * sizeof(int));
   if(char_array == NULL)
   {
      FatalError("Not enough memory!");
   }

   for(i = 0; i < MAX_ARRAY; i++)
   {
      char_array[i] = 0;
   }

   while(c != EOF)
     { c = fgetc(fp);
      char_array[c]++;
   }

   return char_array;
}