#include
#include
#include
#include
#include
#include
using namespace std;
#define _CRT_SECURE_NO_DEPRECATE 1
#define _CRT_NONSTDC_NO_DEPRECATE 1
typedef long long LongType;
struct CharInfo
{
char _ch;
LongType _count;
string _code;
CharInfo(LongType count = 0)
:_count(count)
{}
bool operator<(const CharInfo& info)const
{
return _count < info._count;
}
CharInfo operator+(const CharInfo& info)const
{
return CharInfo(_count + info._count);
}
bool operator!=(const CharInfo& info)const
{
return _count != info._count;
}
};
template
struct HuffmanTreeNode
{
HuffmanTreeNode* _left;
HuffmanTreeNode* _right;
T _weight;//权重
HuffmanTreeNode(T& weight)
:_left(NULL)
, _right(NULL)
, _weight(weight)
{}
};
template>
class Heap
{
public:
//vector调用自己的构造函数
Heap()
{}
Heap(T* a, size_t size)
{
for (size_t i = 0; i < size; ++i)
_array.push_back(a[i]);
//size-1是数组最大下标，再减1除二是父节点下标
for (int i = (_array.size() - 1 - 1) / 2; i >= 0; --i)
{
AdjustDown(i);
}
}
void Push(const T& x)
{
_array.push_back(x);
AdjustUp(_array.size() - 1);
}
void Pop()
{
if (_array.size()>0)
{
swap(_array[_array.size() - 1], _array[0]);
_array.pop_back();
AdjustDown(0);
}
}
int Size()
{
return _array.size();
}
T Top()
{
if (Size() > 0)
{
return _array[0];
}
}
protected:
void AdjustDown(int prtIndex)
{
int leftIndex = 0;
while (prtIndex<_array.size())
{
leftIndex = prtIndex * 2 + 1;
//此处应对称方法，传递的参数，比较大小：
if (leftIndex + 1 < _array.size() && _com(_array[leftIndex + 1], _array[leftIndex]))
leftIndex = leftIndex + 1;
if (leftIndex<_array.size() && _com(_array[leftIndex], _array[prtIndex]))
{
swap(_array[prtIndex], _array[leftIndex]);
prtIndex = leftIndex;
}
else
break;
}
}
void AdjustUp(int chiIndex)
{
int parIndex = (chiIndex - 1) / 2;
while (chiIndex > 0)//父节点不会小于0，（0-1）/2等于0，此处应用chiIndex来判断
{
if (_com(_array[chiIndex], _array[parIndex]))
{
swap(_array[parIndex], _array[chiIndex]);
chiIndex = parIndex;
parIndex = (chiIndex - 1) / 2;
}
else
break;
}
}
protected:
vector _array;
Comp _com;
};
template
class HuffmanTree
{
typedef HuffmanTreeNode Node;
public:
HuffmanTree(T* a,int size, T& invalid)
:_root(NULL)
{
struct HuffmanCompare
{
bool operator()(Node*& l,Node*& r)
{
return l->_weight < r->_weight;
}
};
Heap minHeap;
for (int i = 0; i < size; ++i)
{
if (a[i] != invalid)
minHeap.Push(new Node(a[i]));
}
Node *left,*right,*parent;//指针定义，*和名字在一起
while (minHeap.Size()>1)
{
left = minHeap.Top();
minHeap.Pop();
right = minHeap.Top();
minHeap.Pop();
parent = new Node(left->_weight+ right->_weight);
parent->_left = left;
parent->_right = right;
minHeap.Push(parent);
}
_root = minHeap.Top();
minHeap.Pop();
}
Node* GetRoot()
{
return _root;
}
private:
Node* _root;
};
class FileCompress
{
protected:
CharInfo _infos[256];//存储所有字符
public:
FileCompress()
{
for (int i = 0; i < 256; ++i)
{
_infos[i]._ch = i;
_infos[i]._count = 0;
}
}
void Compress(const char* filename)
{
FILE* fout = fopen(filename, "r");
assert(fout);//判断指针非空
int ch = fgetc(fout);//读取到EOF
while (ch != EOF)
{
_infos[(unsigned char)ch]._count++;
ch = fgetc(fout);
}
//建哈夫曼树
CharInfo invalid;
HuffmanTree tree(_infos, 256, invalid);
//生成哈夫曼编码
string code;
GenerateHuffmanCode(tree.GetRoot(), code);
string compressFilename = filename;
compressFilename += ".compress";
FILE* fin = fopen(compressFilename.c_str(), "w");
assert(fin);
fseek(fout, 0, SEEK_SET);
ch = fgetc(fout);
int value = 0;
int size = 0;
while (ch != EOF)
{
string& _c_code = _infos[(unsigned char)ch]._code;
for (int i = 0; i < _c_code.size(); ++i)
{
value <<= 1;
if (_c_code[i] == '1')
value |= 1;
++size;
if (size == 8)
{
fputc(value, fin);
size = 0;
value = 0;
}
}
ch = getc(fout);
}
//不满8位，低位补0
if (size)
{
value <<= (8 - size);
fputc(value, fin);
}
//写配置文件
string configName = filename;
configName += ".config";
FILE* fInconfig = fopen(configName.c_str(),"w");
assert(fInconfig);
for (int i = 0; i < 256; ++i)
{
string line;
char _buf[20];
if (_infos[i]._count>0)
{
memset(_buf, 0, sizeof(_buf));
line += _infos[i]._ch;
line += ',';
line+=_itoa(_infos[i]._count, _buf, 10);
line += '\n';
fputs(line.c_str(), fInconfig);
}
}
fclose(fin);
fclose(fout);
fclose(fInconfig);
}
void UnCompress(const char* filename)
{
string compressFilename = filename;
compressFilename += ".compress";
FILE* fout = fopen(compressFilename.c_str(), "r");
assert(fout);
int ch = getc(fout);
//重建哈夫曼树
string configFilename = filename;
configFilename += ".config";
FILE* foutConfig = fopen(configFilename.c_str(), "r");
assert(foutConfig);
//解析配置文件
string line;
while (ReadLine(foutConfig, line))
{
if (line.empty())//空行
{
line += '\n';
}
else
{
// _infos[(unsigned char)line[0]]._count = atoi(&line[2]);
_infos[(unsigned char)line[0]]._count = atoi(line.substr(2).c_str());
line.clear();
}
}
CharInfo invalid;
HuffmanTree tree(_infos, 256, invalid);
//解压缩不需要哈夫曼编码
HuffmanTreeNode* root = tree.GetRoot();
HuffmanTreeNode* cur = root;
string uncompressFilename = filename;
uncompressFilename += ".uncompress";
FILE* fin = fopen(uncompressFilename.c_str(), "w");
assert(fin);
int pos = 7;
while (ch != EOF)
{
if (ch&(1 << pos))
cur = cur->_right;
else
cur = cur->_left;
if (cur->_left == NULL&&cur->_right == NULL)
{
fputc(cur->_weight._ch, fin);
cur = root;
}
--pos;
if (pos < 0)
{
ch = getc(fout);
pos = 7;
}
}
}
bool ReadLine(FILE* fout, string& line)
{
int ch = fgetc(fout);
while (ch != EOF&&ch != '\n')
{
line += ch;
ch = fgetc(fout);
}
if (ch == '\n')
return true;
else
return false;
}
void GenerateHuffmanCode(HuffmanTreeNode* root, string code)
{
if (root == NULL)
return;
if (root->_left == NULL&&root->_right == NULL)
{
_infos[root->_weight._ch]._code = code;
return;
}
GenerateHuffmanCode(root->_left, code + '0');
GenerateHuffmanCode(root->_right, code + '1');
}
};
void TestCompress()
{
FileCompress f;
f.Compress("input.txt");
}
void TestUnCompress()
{
FileCompress f;
f.UnCompress("input.txt");
}
#include"Huffman.h"
int main()
{
TestCompress();
TestUnCompress();
system("pause");
return 0;
}
文章标题：文件压缩项目
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http://cdxtjz.cn/article/jjiijs.html
