void generateCodes(const iNode *node, const HuffCode &prefix, HuffCodeMap &outCodes){
if (const leafNode *lf = dynamic_cast<const leafNode*>(node))
outCodes[lf->c] = prefix;
else if (const intNode *in = dynamic_cast<const intNode*>(node)){
HuffCode leftPrefix = prefix;
leftPrefix.push_back(false);
generateCodes(in->left, leftPrefix, outCodes);
HuffCode rightPrefix = prefix;
rightPrefix.push_back(true);
generateCodes(in->right, rightPrefix, outCodes);
}
}
void GenerateCodes(const INode* node, const HuffCode& prefix, HuffCodeMap& outCodes)
{
if (const LeafNode* lf = dynamic_cast<const LeafNode*>(node))
{
outCodes[lf->c] = prefix;
}
else if (const InternalNode* in = dynamic_cast<const InternalNode*>(node))
{
HuffCode leftPrefix = prefix;
leftPrefix.push_back(false);
GenerateCodes(in->left, leftPrefix, outCodes);
HuffCode rightPrefix = prefix;
rightPrefix.push_back(true);
GenerateCodes(in->right, rightPrefix, outCodes);
}
}
void huffman(OCTET *in, int width, int height) {
int frequencies[UniqueSymbols] = {0};
for (int i = 0; i < width * height; i++) {
frequencies[in[i]]++;
}
INode* root = BuildTree(frequencies);
HuffCodeMap codes;
GenerateCodes(root, HuffCode(), codes);
delete root;
std::stack<bool> *vec = new std::stack<bool>();
for (int i = 0; i < width * height; i++) {
HuffCode c = codes.find(in[i])->second;
std::for_each(c.begin(), c.end(), [=](bool b) {
vec->push(b);
});
if(vec->size() > 8) {
std::cout << toChar(vec);
}
}
}
// 重新建立哈夫曼树
INode* BuildTree(HuffCodeMap& dir)
{
InternalNode* root = new InternalNode();
for (HuffCodeMap::iterator it = dir.begin(); it != dir.end(); ++it)
{
HuffCode codes = it->second;
// 中间只建立父节点
InternalNode* sroot = root;
HuffCode::iterator subit = codes.begin();
for (; subit != codes.end() - 1; ++subit)
{
// 右节点
if (*subit == 't')
{
// 空
if (sroot->right == NULL)
{
InternalNode* node = new InternalNode();
sroot->right = node;
sroot = node;
}
else
{
sroot = (InternalNode*)sroot->right;
}
}
// 左节点
else
{
if (sroot->left == NULL)
{
InternalNode* node = new InternalNode();
sroot->left = node;
sroot = node;
}
else
{
sroot = (InternalNode*)sroot->left;
}
}
}
// 最后建立叶节点,用1表示叶节点
LeafNode* node = new LeafNode(1, it->first);
// 右节点
if (*subit == 't')
{
// 空
if (sroot->right == NULL)
{
sroot->right = node;
sroot = (InternalNode*)node;
}
else
{
sroot = (InternalNode*)sroot->right;
}
}
// 左节点
else
{
if (sroot->left == NULL)
{
sroot->left = node;
sroot = (InternalNode*)node;
}
else
{
sroot = (InternalNode*)sroot->left;
}
}
}
return root;
}
