本文主要是介绍中文压缩和解码程序设计与实现（huffman），希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
本项目是利用huffman算法进行中文压缩和解码的设计与实现，huffman算法被证明是最优的结构，可以用于数据压缩
源码
/**************************************************************************************
** this function is about to compress a file with chinese code
** by using huffman method
** NEWPLAN @ UESTC 2014.5
****************************************************************************************/
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>#define SUCCESS 1
#define FAILURE 0
#define DICTIONRAY 0
#define INDEX 1/*used to calculate the frequence of character has shown*******/
int array_char[256]= {0};
unsigned char amounts=0;
/*******define a strcuture to hold the tree node***************/
#pragma pack(1)
typedef struct huff
{struct huff *lchild,*rchild,*parent;int wight;unsigned char code;
} HUFF_NODE,*HUFF_NODE_PTR;
#pragma pack()/*HEAD of tree*/
HUFF_NODE_PTR HUFF_HEADER=NULL;
/*dictionary of characters maybe not been used all just for convenient*/
char* HUFF_DICTIONARY[256]= {0};
HUFF_NODE_PTR huff_pt[256];void help(void);
void version(void);
void output(char*);
void initilize(void);
int claculate(FILE*);
int create_dictiony(void);
void compress(const char*);
int file_write(char*,FILE*);
void write_dictionary(char*);
FILE* file_open(const char*);
int create_tree(HUFF_NODE_PTR* );
void decompress_func(const char*);
void decode (HUFF_NODE_PTR,FILE*);
HUFF_NODE_PTR tree_from_dic(char**);
HUFF_NODE_PTR huff_malloc(unsigned char i);
void swap_func(unsigned char *,unsigned char*);
HUFF_NODE_PTR adjusty(HUFF_NODE_PTR code[] ,size_t);//********************************************************
// Method: main
// FullName: main
// Access: public
// Returns: int
// Qualifier: the entry function
// Parameter: int argc the parameter count
// Parameter: char const * argv[] array of hold parameter
//********************************************************
int main(int argc, char const *argv[])
{initilize();if(argc<2){printf("can`t be empty file or operation\n");return FAILURE;}// if((file_index=file_open(argv[argc-1]))==NULL)if (!stricmp(argv[1],"--help")){help();return SUCCESS;}else if (!stricmp(argv[1],"--version")){version();return SUCCESS;}else if (!stricmp(argv[1],"-c")){compress(argv[2]);}else if(!stricmp(argv[1],"-z")){decompress_func(argv[2]);}elsehelp();return SUCCESS;
}//************************************
// Method: initilize
// FullName: initilize
// Access: public
// Returns: void
// Qualifier: inites
// Parameter: void
//************************************
void initilize(void)
{int calcount=0;//memset(array_char,'0',sizeof(array_char));while(calcount<256){array_char[calcount]=0;huff_pt[calcount]=NULL;HUFF_DICTIONARY[calcount]=0;calcount++;}return ;
}//************************************
// Method: file_open
// FullName: file_open
// Access: public
// Returns: FILE*
// Qualifier: open the input file
// Parameter: const char * file_name
//************************************
FILE* file_open(const char* file_name)
{FILE* file_index=NULL;if((file_index=fopen(file_name,"r"))==NULL)return NULL;return file_index;
}//******************************************************************
// Method: claculate
// FullName: claculate
// Access: public
// Returns: int
// Qualifier: calculate the frequence of character in file_index
// Parameter: FILE * file_index
//****************************************************************
int claculate(FILE* file_index)
{unsigned char temp=0;while(!feof(file_index)){/*eat file*/if(fread(&temp,sizeof(unsigned char),1,file_index))array_char[temp]++;}return SUCCESS;
}//************************************
// Method: create_dictiony
// FullName: create_dictiony
// Access: public
// Returns: int
// Qualifier:create dictionary
// Parameter: void
//************************************
int create_dictiony(void)
{int i=0;char *u=NULL;unsigned char j=0;HUFF_NODE_PTR head,currents=NULL;create_tree(&head);HUFF_HEADER=head;while(i<256){if(huff_pt[i]!=NULL){currents=huff_pt[i];j=currents->code;u=malloc(sizeof(char));assert(u!=NULL);memset(u,0,sizeof(char));while(currents->parent!=NULL){u=realloc(u,2*sizeof(char)+strlen(u));assert(u!=NULL);if(currents->parent->lchild==currents)strcat(u,"0");else if(currents->parent->rchild==currents)strcat(u,"1");else{printf("error in code\n");system("pasue");}currents=currents->parent;}/*reverse*/strrev(u);HUFF_DICTIONARY[j]=u;}i++;}return SUCCESS;
}
//************************************
// Method: create_tree
// FullName: create_tree
// Access: public
// Returns: int
// Qualifier:create tree of huffman
// Parameter: HUFF_NODE_PTR * head
//************************************
int create_tree(HUFF_NODE_PTR* head)
{size_t n=256,i,j;HUFF_NODE_PTR temp[256];memset(temp,0,sizeof(temp));for (i = 0,j=0; i < n; i++){if(array_char[i]){temp[j] = huff_malloc((unsigned char)i);temp[j]->wight = array_char[i];/*temp[j]->code is the code that contain the info of read_file*/temp[j]->code = i;huff_pt[i]=temp[j];j++;}}*head=adjusty(temp,j);amounts=j;return SUCCESS;
}//************************************
// Method: file_write
// FullName: file_write
// Access: public
// Returns: int
// Qualifier:create function
// Parameter: char * file_name
// Parameter: char * file_stream
// Parameter: size_t num
// Parameter: int flags
//************************************
int file_write(char* file_name,FILE* file_inputs)
{FILE* fp=NULL;int counts=0;unsigned char readdata,writedata=0,*TempPoint;char* file_w=file_name;fp=fopen(file_w,"ab+");if(!fp){printf("can`t open file %s and exit FAILURE!\n", file_name);exit(FAILURE);}while(!feof(file_inputs)){if(fread(&readdata,sizeof(unsigned char),1,file_inputs))TempPoint=(unsigned char*)HUFF_DICTIONARY[readdata];while(*TempPoint){writedata=writedata<<1;writedata|=(*TempPoint-'0');TempPoint++;counts++;if(counts==8){fwrite(&writedata,sizeof(unsigned char),1,fp);counts=0;writedata=0;}}}if(counts){writedata<<=(8-counts);fwrite(&writedata,sizeof(unsigned char),1,fp);}writedata=(unsigned char)((8-counts)%8);fwrite(&writedata,sizeof(unsigned char),1,fp);fclose(fp);return SUCCESS;
}//************************************
// Method: huff_malloc
// FullName: huff_malloc
// Access: public
// Returns: HUFF_NODE_PTR
// Qualifier:
// Parameter: unsigned char i
//************************************
HUFF_NODE_PTR huff_malloc(unsigned char i)
{HUFF_NODE_PTR temp=(HUFF_NODE_PTR)malloc(sizeof(HUFF_NODE));assert (temp!=NULL);temp->code=i;temp->parent=NULL;temp->lchild=NULL;temp->rchild=NULL;temp->wight=0;return temp;
}//************************************
// Method: adjusty
// FullName: adjusty
// Access: public
// Returns: HUFF_NODE_PTR
// Qualifier:
// Parameter: HUFF_NODE_PTR code[]
// Parameter: size_t n
//************************************
HUFF_NODE_PTR adjusty(HUFF_NODE_PTR code[],size_t n)
{assert (n<=256);int i,j=0,k=0;/* index j replcaethe lest,and index k replace the second*/HUFF_NODE_PTR temp=NULL;while(n){for(i=0; i<n; i++){if(code[k]->wight>code[i]->wight){if(code[j]->wight>code[i]->wight){k=j;j=i;}elsek=i;}}/*finished the merge*/if(j==k){if(n==1)break;k++;i=k;while(i<n){if(code[k]->wight>code[i]->wight)k=i;i++;}}temp=huff_malloc(0);/*merge two child*/temp->lchild=code[j];temp->rchild=code[k];/*child pointer point to parent*/code[j]->parent=temp;code[k]->parent=temp;temp->wight=code[j]->wight+code[k]->wight;if(j<k){code[j]=temp;if(k!=(--n))code[k]=code[n];}else{code[k]=temp;if(j!=(--n))code[j]=code[n];}k=0;j=0;}return temp;
}//************************************
// Method: decode
// FullName: decode
// Access: public
// Returns: void
// Qualifier:
// Parameter: HUFF_NODE_PTR head
// Parameter: FILE * fp
//************************************
void decode (HUFF_NODE_PTR head,FILE* fp)
{unsigned char read_code,tempcode=0,rewards=0,tp=0;int count=8,model=0;int flags=0;HUFF_NODE_PTR decode_head=head;unsigned char CHINESE[3]= {0,0,0};while(!feof(fp)){backup:count=8;/*get a 8 bits code to find the leaves*/fread(&tempcode,sizeof(unsigned char),1,fp);/*if arrive to last second character you shouldexit now !*/if(feof(fp))break;read_code=tempcode;while(decode_head){/*go to the leave note!,should to decode now*/if(!decode_head->lchild){fread(&rewards,sizeof(unsigned char),1,fp);fread(&tp,sizeof(unsigned char),1,fp);/*arrive to second character*/model++;model%=2;CHINESE[model]=decode_head->code;if(CHINESE[(model-1+2)%2]>0xa0){if(!model)swap_func(&CHINESE[0],&CHINESE[1]);printf("%s",CHINESE);CHINESE[0]=CHINESE[1]=0;}else if (CHINESE[model]<0xa0){printf("%c",CHINESE[model]);}decode_head=head;if(feof(fp)){ungetc((char)tp,fp);ungetc((char)rewards,fp);flags=1;break;}fseek(fp,-2,SEEK_CUR);}/*left child should be 1,and else the opposite*/if(read_code&0x80){decode_head=decode_head->rchild;}elsedecode_head=decode_head->lchild;read_code<<=1;count--;/*if get here means that: a unsigned char temphas been used out and we should start again!*/if(!count)goto backup;}if(flags)break;}assert(count>=rewards);while(count-rewards){if(read_code&0x80){decode_head=decode_head->rchild;}elsedecode_head=decode_head->lchild;read_code<<=1;count--;if(!decode_head->lchild){model++;model%=2;CHINESE[model]=decode_head->code;if(CHINESE[(model-1+2)%2]>0xa0){if(!model)swap_func(&CHINESE[0],&CHINESE[1]);printf("%s",CHINESE);CHINESE[0]=CHINESE[1]=0;}else if (CHINESE[model]<0xa0){printf("%c",CHINESE[model]);}decode_head=head;}}return;
}//************************************
// Method: swap_func
// FullName: swap_func
// Access: public
// Returns: void
// Qualifier:
// Parameter: unsigned char * A
// Parameter: unsigned char * B
//************************************
void swap_func(unsigned char *A,unsigned char *B)
{unsigned temp=*A;*A=*B;*B=temp;return;
}//************************************
// Method: write_dictionary
// FullName: write_dictionary
// Access: public
// Returns: void
// Qualifier: write to file keeping message
// of dictionary
// Parameter: char * file_name
//************************************
void write_dictionary(char* file_name)
{int counts=0,length;FILE* fp=fopen(file_name,"ab+");//char* file_w=(char *)malloc(strlen(file_name)+3);assert(fp!=NULL);/*write to logs*//*write the amount of characters*/fwrite(&amounts,sizeof(unsigned char),1,fp);for(; counts<256;){/*if(current dictionary is not null that means you shouldwrite it to dictionary, causing this is a pointer pointingto a series of decodehere we should write the character ,decode,and its length*/if(HUFF_DICTIONARY[counts]){fwrite(&counts,sizeof(unsigned char),1,fp);length=strlen(HUFF_DICTIONARY[counts]);fwrite(&length,sizeof(int),1,fp);fwrite(HUFF_DICTIONARY[counts],sizeof(unsigned char),length,fp);}counts++;}fclose(fp);return ;
}//************************************
// Method: output
// FullName: output
// Access: public
// Returns: void
// Qualifier:decode and output
// Parameter: char * file_name
//************************************
void output(char* file_name)
{int ch_counts=0,length=0;unsigned char ch_index=0;HUFF_NODE_PTR head_index=NULL;FILE* fp=fopen(file_name,"rb+");assert(fp!=NULL);fread(&ch_counts,sizeof(unsigned char),1,fp);while(ch_counts--){fread(&ch_index,sizeof(unsigned char),1,fp);fread(&length,sizeof(int),1,fp);free(HUFF_DICTIONARY[ch_index]);HUFF_DICTIONARY[ch_index]=(char*)malloc(length+1);memset(HUFF_DICTIONARY[ch_index],0,length+1);fread(HUFF_DICTIONARY[ch_index],sizeof(char),length,fp);}printf("\ndecode start...\n");//create_tree(&head_index);head_index = tree_from_dic(HUFF_DICTIONARY);decode(head_index,fp);printf("\ntranslation has been finished\n");return ;
}void version(void)
{printf("\nCOPYRIGHT @ NEWPLAN IN UESTC\n");printf("CURRENT VERSION IS NEWPLAN.0.1 THANKS FOR SUPPORT US!\n\n");return;
}
void help(void)
{printf("/*********************************************""*********************************\n** by using huffman method\n""** NEWPLAN @ UESTC 2014.5\n*******************************""***********************************************/ \n");printf("choose function to operate!\n");printf("FORMAT:\n");printf("NEWPLAN [parameter] [FILE]\n");printf("this is about compress file to a new file with FORMAT : file_name.n \n");printf("parameter:\n");printf("\t-c\t\tcheck for compress file\n");printf("\t-z\t\tcheck for decompress file\n");printf("\t--help\t\tcheck for documents\n");printf("\t--version\tcheck for version\n");return;
}void compress(const char* file_s)
{char* fw=NULL;FILE* file_index=file_open(file_s);fw=(char*)malloc(strlen(file_s)+3);assert ((file_index!=NULL)&&(fw!=NULL));memset(fw,0,strlen(file_s)+3);strcat(fw,file_s);strcat(fw,".n");claculate(file_index);create_dictiony();write_dictionary(fw);fclose(file_index);file_index=file_open(file_s);file_write(fw,file_index);return;
}void decompress_func(const char* file_s)
{char* fw=(char*)malloc(strlen(file_s)+3);assert(fw!=NULL);memset(fw,0,strlen(file_s)+3);strcat(fw,file_s);strcat(fw,".n");output(fw);return;
}HUFF_NODE_PTR tree_from_dic(char** dic_array)
{int cycle=0;char* ch_ptr=NULL;HUFF_NODE_PTR temp=NULL;HUFF_HEADER=huff_malloc(0);for (cycle = 0; cycle < 256; cycle++){if(dic_array[cycle]){temp=HUFF_HEADER;ch_ptr=dic_array[cycle];while(*ch_ptr){if(*ch_ptr=='0'){if(!temp->lchild){temp->lchild=huff_malloc(0);temp->lchild->parent=temp;}temp=temp->lchild;}else{if(!temp->rchild){temp->rchild=huff_malloc(0);temp->rchild->parent=temp;}temp=temp->rchild;}ch_ptr++;}temp->code=cycle;}}return HUFF_HEADER;
}
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