初始代码:
`int main(int argc, char** argv)
{
fstream inFile;
inFile.open(argv[1]);
//where 'filename' is a string variable containing the filename
if (inFile.fail())
{
cerr<<"Error opening "<<argv[1]<<endl;
exit(1); //terminate the program
}
else{
string word;
AVLTree<WordStat> avl;
BSTree<WordStat> binary;
while(inFile >> word) {
WordStat a(word, 0);
avl.insert(a);
binary.insert(a);
}
cout << "Table 1:Binary Search Tree [" << argv[1] << "]" << endl;
cout << "In-order Traversal" << endl;
cout << "===================================" << endl;
cout << "Word Frequency" << endl;
cout << "----------------------------------" << endl;
while (binary.isEmpty() != true){
binary.traverse(printResults);
}`
二叉树实现:
template <typename E>
BSTree<E>::Node::Node(E s)
{
data = s;
left = NULL;
right = NULL;
}
/* Outer BSTree class definitions */
template <typename E>
BSTree<E>::BSTree()
{
root = NULL;
count = 0;
}
template <typename E>
BSTree<E>::~BSTree()
{
recDestroy(root);
}
template <typename E>
bool BSTree<E>::isEmpty() const
{
return root == NULL;
}
template<typename E>
void BSTree<E>::insert(E item)
{
Node* tmp;
Node* newnode = new Node(item);
/* If it is the first node in the tree */
if (isEmpty())
{
root = newnode;
count++;
return;
}
/*find where it should go */
tmp = root;
while (1)
{
if (tmp->data == item)
{ /* Key already exists. */
tmp->data = item;
delete newnode; /* don’t need it */
return;
}
else if (tmp->data > item)
{
if (!(tmp->left))
{
/* If the key is less than tmp */
tmp->left = newnode;
count++;
return;
}
else
{
/* continue searching for insertion pt. */
tmp = tmp->left;
}
}
else
{
if (!(tmp->right))
{
/* If the key is greater than tmp */
tmp->right = newnode;
count++;
return;
}
else
/* continue searching for insertion point*/
tmp = tmp->right;
}
}
}
template<typename E>
bool BSTree<E>::inTree(E item) const
{
Node* tmp;
if (isEmpty())
return false;
/*find where it is */
tmp = root;
while (1)
{
if (tmp->data == item)
return true;
if (tmp->data > item)
{
if (!(tmp->left))
return false;
/* continue searching */
tmp = tmp->left;
}
else
{
if (!(tmp->right))
return false;
/* continue searching for insertion pt. */
tmp = tmp->right;
}
}
}
template<typename E>
void BSTree<E>::remove(const E& item)
{
Node* nodeptr;
nodeptr = search(item);
if (nodeptr)
{
remove(nodeptr);
count--;
}
}
template<typename E>
const E& BSTree<E>::retrieve(const E& key) const throw (BSTreeException)
{
Node* tmp;
if (isEmpty())
throw BSTreeException("Binary Search Tree Exception: tree empty on retrieve()");
tmp = root;
while(tmp)
{
if (tmp->data == key)
return tmp->data;
if (tmp->data > key)
tmp = tmp->left;
else
tmp = tmp->right;
}
if (tmp == NULL)
throw BSTreeException("Binary Search Tree Exception: key does not exist on retrieve()");
return tmp->data;
}
template<typename E>
void BSTree<E>::traverse(FuncType func)
{
traverse(root,func);
}
template<typename E>
int BSTree<E>::size() const
{
return count;
}
template<typename E>
int BSTree<E>::height() const
{
return height(root);
}
template<typename E>
int BSTree<E>::depth(const E& item) const
{
Node* tmp;
tmp = root;
int depth;
while(tmp != NULL)
{
if (tmp->data == item)
return tmp->data;
if (tmp->data > item)
{
if (tmp->left == NULL)
break;
tmp = tmp->left;
depth++;
}
else
{
if (tmp->right == NULL)
break;
tmp = tmp->right;
depth++;
}
}
return depth;
}
template<typename E>
void BSTree<E>::recDestroy(Node* root)
{
if (root)
{
if (root->left) recDestroy(root->left);
if (root->right) recDestroy(root->right);
delete root;
}
}
template<typename E>
typename BSTree<E>::Node* BSTree<E>::findParent(Node* node)
{
Node* tmp;
tmp = root;
if (tmp == node)
return NULL;
while(1)
{
assert(tmp->data != node->data);
if (tmp->data > node->data)
{
assert(tmp->left != NULL);
if (tmp->left == node)
return tmp;
tmp = tmp->left;
}
else
{
assert(tmp->right != NULL);
if (tmp->right == node)
return tmp;
tmp = tmp->right;
}
}
}
template<typename E>
void BSTree<E>::traverse(Node* node, FuncType func)
{
if (node)
{
traverse(node->left,func);
func(node->data);
traverse(node->right,func);
}
}
template<typename E>
typename BSTree<E>::Node* BSTree<E>::search(const E& item)
{
Node* tmp;
tmp = root;
while(tmp)
{
if (tmp->data == item)
return tmp;
if (tmp->data > item)
tmp = tmp->left;
else
tmp = tmp->right;
}
return tmp;
}
template<typename E>
bool BSTree<E>::remove(Node* node)
{
E data;
Node* parent;
Node* replacement;
parent = findParent(node);
if (node->left && node->right)
{
replacement = node->right;
while (replacement->left)
replacement = replacement->left;
data = replacement->data;
remove(replacement);
node->data = data;
return true;
}
else
{
if (node->left)
replacement = node->left;
else if (node->right)
replacement = node->right;
else
replacement = NULL;
if (!parent)
root = replacement;
else if (parent->left == node)
parent->left = replacement;
else
parent->right = replacement;
delete node;
return true;
}
}
template<typename E>
int BSTree<E>::height(Node* node) const
{
int h = 0;
if (node != NULL)
{
int l_height = height(node->left);
int r_height = height(node->right);
int max_height = max(l_height, r_height);
h = max_height + 1;
}
return h;
}
template<typename E>
void BSTree<E>::levelTraverse(FuncType func)
{
queue<E> q;
q.push(root);
while (q.empty() != true){
Node *tmp = q.pop();
func(tmp);
q.push(tmp->left);
q.push(tmp->right);
}
}
运行上面的main时，会导致二叉树中的横向函数报错如下“main.cpp:67:36: error: invalid conversion from 'void ()(WordStat)' to ' BSTree::FuncType {aka void ()(const WordStat&)}' [-fpermissive] binary.traverse(printResults);"
想知道是否有人有解决此问题的线索。谢谢!
最佳答案
我认为将 printResults 接口(interface)更改为 void printResults(const WordStat&) 将解决问题
关于c++ - 尝试在 FuncType 参数中使用 Void 函数时遇到错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/42791210/