需要帮助遍历树;霍夫曼编码
Need help traversing a tree; Huffman Coding
我已经创建了一个霍夫曼树,它似乎是正确的,但是当涉及到遍历数据结构时,我很弱。我根据根树中包含的信息在纸上画出了树,看起来很好,但是我的代码有问题,我不知道如何修复它。
第一个0是持久的,每次右移时,它似乎在后面附加了一个0。
example:
L: 01
H: 1111
but my traversal gives me:
L: 001
H: 01010101
代码片段struct node
{
int symbol;
int frequency;
node* left;
node* right;
};
void Huffman::generateCode(node *tree, std::string code)
{
if(tree->left == NULL && tree->right == NULL)
{
//std::cout << "Leaf Found: " << tree->symbol << "t" << code << std::endl;
mapCode.insert(std::pair<int, std::string>(tree->symbol,code));
}
if(tree->left != NULL)
{
code.append("0");
generateCode(tree->left, code);
}
if(tree->right != NULL)
{
code.append("1");
generateCode(tree->right, code);
}
}
UPDATE SOLVED: i figure out the code.append();函数把它搞砸了。我把它改成code + "0";
void Huffman::generateCode(node *tree, std::string code)
{
if(tree->left == NULL && tree->right == NULL)
{
std::cout << "Leaf Found: " << tree->symbol << "t" << code << std::endl;
mapCode.insert(std::pair<int, std::string>(tree->symbol,code));
}
if(tree->left != NULL)
{
generateCode(tree->left, code + "0");
}
if(tree->right != NULL)
{
generateCode(tree->right, code + "1");
}
}
您错过了else
:
void Huffman::generateCode(node *tree, std::string code)
{
if(tree->left == NULL && tree->right == NULL)
{
//std::cout << "Leaf Found: " << tree->symbol << "t" << code << std::endl;
mapCode.insert(std::pair<int, std::string>(tree->symbol,code));
}
else if(tree->left != NULL)
{
code.append("0");
generateCode(tree->left, code);
}
else if(tree->right != NULL)
{
code.append("1");
generateCode(tree->right, code);
}
}