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huffman
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@gensokyoukiyoe
gensokyoukiyoe committed Dec 28, 2016
1 parent 47e1132 commit 1ff5660
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#include<iostream>
#include<malloc.h>
#include<string.h>
#include<algorithm>
#include<map>
#include<vector>
#define ll long long

using namespace std;

typedef struct {
int sign;
int weight;
int parent;
int lchild;
int rchild;
}HTNode;
typedef HTNode *HuffmanTree;

typedef struct{
int name;
int cnt;
}Code;


void Select(HuffmanTree &HT,int a,int &s1,int &s2);
HuffmanTree Create(Code f[],int n){
int m=2*n-1;
HuffmanTree HT =new HTNode[m+1];
int s1,s2;
for(int i=1;i<=m;i++){
HT[i].lchild=0,HT[i].rchild=0,HT[i].parent=0,HT[i].weight=0;
}


int head=1;
for(int i=0;i<256;i++){
if(f[i].cnt>0){
HT[head].sign=f[i].name;
HT[head++].weight=f[i].cnt;
}
}

for(int i=n+1;i<=m;i++){
Select(HT,i-1,s1,s2);
HT[s1].parent = i,HT[s2].parent=i;
HT[i].lchild = s1;HT[i].rchild=s2;
HT[i].weight = HT[s1].weight + HT[s2].weight;
}
return HT;
}

void Select(HuffmanTree &HT,int a,int &s1,int &s2){
int i,j,x,y;
for(j=1;j<=a;j++){
if(HT[j].parent==0){
x=j;
break;
}
}
for(i=1;i<=a;i++){
if(HT[i].weight<HT[x].weight&&HT[i].parent==0){
x=i;
}
}
for(j=1;j<=a;j++){
if(HT[j].parent==0&&j!=x){
y=j;
break;
}
}
for(i=1;i<=a;i++){
if(HT[i].weight<HT[y].weight&&HT[i].parent==0&&i!=x){
y=i;
}
}
s1=x,s2=y;
}

typedef char ** HuffmanCode;
void CrtHuffmanCode1(HuffmanTree ht,HuffmanCode hc,int n){
char *cd;
int start;
cd =(char *)malloc(sizeof(char)*n);
cd[n-1]='\0';

for(int i=1;i<=n;i++){
int start=n-1;
int c=i;
int p=ht[i].parent;
while(p!=0){
--start;
if(c==ht[p].lchild)
cd[start]='0';
else if(c==ht[p].rchild)
cd[start]='1';

c=p;
p=ht[p].parent;
}
hc[i]=(char*)malloc( (n-start) * sizeof(char) );
strcpy(hc[i],&cd[start]);
}
free(cd);
}


// ---------- 将二进制码 还原成源文件 ----------------
void Decode(string s,HuffmanTree ht,int n,int tail,char *filename){
string s1(filename);
string s2(".decode");
string s3=s1+s2;
FILE *fout;
if((fout=fopen(s3.c_str(),"wb"))==NULL){
printf("write decode error\n");
}

int j=2*n-1;
int i=0;
for(int i=0;i<s.length()-(8-tail);i++)
{
if(s[i]=='0')
j=ht[j].lchild;
else
j=ht[j].rchild;
if(ht[j].lchild==0){
fputc(ht[j].sign,fout);
j=2*n-1;
}
}
fclose(fout);
}


bool cmp(Code a,Code b){
return a.cnt>b.cnt;
}

Code f[256];


int compress(string str,char *filename){

string s1(filename);
string s2(".code");
string s3=s1 + s2;
FILE *ostream;
//cout<<s3<<endl;
if((ostream=fopen(s3.c_str(),"ab+"))==NULL){
cout<<"read code error"<<endl;
}
fseek(ostream,0,SEEK_END);
int cnt=0;
int sum=0;

//string str="0111111101";
int tail=str.length()%8;

putw(tail,ostream);
int end=str.length()-tail;
for(int i=0;i<end;i++){
cnt++;
sum <<=1;
sum |=str[i]-'0';
if(cnt %8==0 &&cnt){
//cout<<sum<<endl;
fputc(sum,ostream);
sum=0;
}
}
//cout<<"sum="<<sum<<endl;
//sum=0;
for(int i=end;i<str.length();i++){
if(str[i]=='1'){
int ret=1;
ret <<=(7-(i-end));
sum +=ret;
}
}
//cout<<sum<<endl;
fputc(sum,ostream);
fclose(ostream);
return tail;
}

string depress(char *filename){
string s1(filename);
string s2(".code");
string s3=s1+s2;
FILE *fp;
if((fp=fopen(s3.c_str(),"rb"))==NULL){
printf("fopen code error");
}
int c;
string str="";
while((c=fgetc(fp))!=EOF){
for(int i=7;i>=0;i--){
int ret=1;
ret <<=i;
if(c&ret){
//cout<<"1";
str+="1";
}
else{
str+="0";
}
}

}
fclose(fp);
return str;
}

int pd(char *argv){
int len=strlen(argv);
string tmp_s2(argv);
int flag=0;
int index;
int sublen=0;
for(int i=len-1;i>=0;i--){
if(argv[i]=='.'){
flag=1;
index=i;
break;
}
sublen++;
}
if(flag==1){
tmp_s2=tmp_s2.substr(index+1,sublen);
if(strcmp("png",tmp_s2.c_str())==0){
//cout<<tmp_s2<<endl;
return 1;
}
if(strcmp("jpg",tmp_s2.c_str())==0){
//cout<<tmp_s2<<endl;
return 2;
}


}
return 0;
}
int main(int argc,char **argv)
{

//freopen("out.txt","w",stdout);

int filetype=pd(argv[1]);
FILE *istream;
if((istream=fopen(argv[1],"rb"))==NULL){
cout<<"fopen argv[1] error"<<endl;
}
int ret[10];
if(filetype==1){
for(int i=0;i<8;i++){
ret[i]=fgetc(istream);
}
//ret1=fgetc(istream);
//ret2=fgetc(istream);
}
if(filetype==2){
for(int i=0;i<6;i++){
ret[i]=fgetc(istream);
}
}

memset(f,0,sizeof(f));

vector<int> all_string;
int n=0; //哈夫曼树中节点的个数
int c;
while((c=getc(istream))!=EOF){
f[c].name=c;
++f[c].cnt;
all_string.push_back(c);
//c=fgetc(istream);
//fread((char*)&c,sizeof(unsigned char),1,istream);
}
fclose(istream);

//cout<<"hello world"<<endl;
/* ---------测验统计 ------------------*/
//cout<<"sdsdas"<<endl;
string tmp_s1=string(argv[1])+".code";
FILE *ostream;
if((ostream=fopen(tmp_s1.c_str(),"wb"))==NULL){
printf("fopen out.tmp error\n");
}

if(filetype==1){
for(int i=0;i<8;i++){
fputc(ret[i],ostream);
}
}
if(filetype==2){
for(int i=0;i<6;i++){
fputc(ret[i],ostream);
}
}

for(int i=0;i<256;i++){
if(f[i].cnt>0){
n++;
//cout<<i<<" "<<f[i].cnt<<endl;
//fwrite(&f[i],sizeof(f[i]),1,ostream);
}
}
int ptr=n;
//cout<<"ptr="<<ptr<<endl;
putw(ptr,ostream);
//fwrite(&ptr,sizeof(int),1,ostream);
for(int i=0;i<256;i++){
if(f[i].cnt>0){
//n++;
//cout<<i<<" "<<f[i].cnt<<endl;
fwrite(&f[i],sizeof(f[i]),1,ostream);
}
}
fclose(ostream);



HuffmanTree ht=Create(f,n);
int m=2*n-1;

HuffmanCode hc=(char**)malloc(sizeof(char*)*(n+1));
for(int i=1;i<=n;i++)
hc[i]=(char*)malloc(sizeof(char)*n);


// ------创建哈弗曼树 --------
CrtHuffmanCode1(ht,hc,n);
/*
for(int i=1;i<=n;i++){
cout<<ht[i].sign<<" "<<hc[i]<<endl;
}
*/
//cout<<"all_string="<<all_string<<endl;
// -------------将二进制码写入code 文件-------------

string tmp_string="";
for(vector<int>::iterator i=all_string.begin();i!=all_string.end();i++){
for(int j=1;j<=n;j++){
if(ht[j].sign==*i){
tmp_string +=hc[j];
break;
}
}
}

//cout<<"tmp_string="<<tmp_string<<endl;
//char ttt[]="in2";
int tail=compress(tmp_string,argv[1]);


/*
// -----------读取 code 文件 还原原文件------
string s2=depress(argv[1]);
Decode(s2,ht,n,tail,argv[1]);
*/

return 0;
}
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