c++ - 二叉搜索树未将插入值加载到树中
问题描述
我的问题是尝试获取函数treeLeavesCount()
并treeNodeCount()
返回树中叶子和节点的值但是,我的问题是在使用insert()
函数通过 while 循环提供值之后,树似乎保持为空,我通过isEmpty()
之前使用函数知道这一点并在将值插入树之后。
主文件
#include <iostream>
#include "binaryTreeType.h"
#include "bSearchTreeType.h"
using namespace std;
int main()
{
int num;
bSearchTreeType<int> *myTree= new bSearchTreeType<int>();
//test if tree is empty
if(myTree->isEmpty())
cout << "yes" << endl;
else
cout << "no" << endl;
cout << "Line 10: Enter numbers ending with -999"<< endl;
cin >> num;
while (num != -999)
{
myTree->insert(num);
cin >> num;
}
myTree->inorderTraversal();
int p;
p=myTree->treeNodeCount();
cout << p << endl;
p=myTree->treeLeavesCount();
cout << p << endl;
//test if tree is empty after data is inserted
if(myTree->isEmpty())
cout << "yes" << endl;
else
cout << "no" << endl;
delete myTree;
return 0;
}
binaryTreeType.h
#ifndef BINARYTREETYPE_H
#define BINARYTREETYPE_H
#include <queue>
template <class elemType>
struct binaryTreeNode
{
elemType info;
binaryTreeNode<elemType> *llink;
binaryTreeNode<elemType> *rlink;
};
template <class elemType>
class binaryTreeType
{
public:
const binaryTreeType<elemType>& operator=(const binaryTreeType<elemType>&);
//Overload the assignment operator.
bool isEmpty() const;
//Returns true if the binary tree is empty;
//otherwise, returns false.
void inorderTraversal() const;
//Function to do an inorder traversal of the binary tree.
void preorderTraversal() const;
//Function to do a preorder traversal of the binary tree.
void postorderTraversal() const;
//Function to do a postorder traversal of the binary tree.
int treeHeight() const;
//Returns the height of the binary tree.
int treeNodeCount() const;
//Returns the number of nodes in the binary tree.
int treeLeavesCount() const;
//Returns the number of leaves in the binary tree.
void destroyTree();
//Deallocates the memory space occupied by the binary tree.
//Postcondition: root = NULL;
binaryTreeType(const binaryTreeType<elemType>& otherTree);
//copy constructor
binaryTreeType();
//default constructor
~binaryTreeType();
//destructor
protected:
binaryTreeNode<elemType> *root;
private:
void copyTree(binaryTreeNode<elemType>* &copiedTreeRoot,binaryTreeNode<elemType>* otherTreeRoot);
//Makes a copy of the binary tree to which
//otherTreeRoot points. The pointer copiedTreeRoot
//points to the root of the copied binary tree.
void destroy(binaryTreeNode<elemType>* &p);
//Function to destroy the binary tree to which p points.
//Postcondition: p = NULL
void inorder(binaryTreeNode<elemType> *p) const;
//Function to do an inorder traversal of the binary
//tree to which p points.
void preorder(binaryTreeNode<elemType> *p) const;
//Function to do a preorder traversal of the binary
//tree to which p points.
void postorder(binaryTreeNode<elemType> *p) const;
//Function to do a postorder traversal of the binary
//tree to which p points.
int height(binaryTreeNode<elemType> *p) const;
//Function to return the height of the binary tree
//to which p points.
int max(int x, int y) const;
//Returns the larger of x and y.
int nodeCount(binaryTreeNode<elemType> *p) const;
//Function to return the number of nodes in the binary
//tree to which p points
int leavesCount(binaryTreeNode<elemType> *p) const;
//Function to return the number of leaves in the binary
//tree to which p points
};
template <class elemType>
bool binaryTreeType<elemType>::isEmpty() const
{
return (root == NULL);
};
template <class elemType>
binaryTreeType<elemType>::binaryTreeType()
{
root = NULL;
}
template <class elemType>
void binaryTreeType<elemType>::inorderTraversal() const
{
inorder(root);
}
template <class elemType>
void binaryTreeType<elemType>::preorderTraversal() const
{
preorder(root);
}
template <class elemType>
void binaryTreeType<elemType>::postorderTraversal() const
{
postorder(root);
}
template <class elemType>
int binaryTreeType<elemType>::treeHeight() const
{
return height(root);
}
template <class elemType>
int binaryTreeType<elemType>::treeNodeCount() const
{
return nodeCount(root);
}
template <class elemType>
int binaryTreeType<elemType>::treeLeavesCount() const
{
return leavesCount(root);
}
template <class elemType>
void binaryTreeType<elemType>::inorder(binaryTreeNode<elemType> *p) const
{
if (p != NULL)
{
inorder(p->llink);
std::cout << p->info << " ";
inorder(p->rlink);
}
}
template <class elemType>
void binaryTreeType<elemType>::preorder(binaryTreeNode<elemType> *p) const
{
if (p != NULL)
{
std::cout << p->info << " ";
preorder(p->llink);
preorder(p->rlink);
}
}
template <class elemType>
void binaryTreeType<elemType>::postorder(binaryTreeNode<elemType> *p) const
{
if (p != NULL)
{
postorder(p->llink);
postorder(p->rlink);
std::cout << p->info << " ";
}
}
template <class elemType>
int binaryTreeType<elemType>::height(binaryTreeNode<elemType> *p) const
{
if (p == NULL)
return 0;
else
return 1 + max(height(p->llink), height(p->rlink));
}
template <class elemType>
int binaryTreeType<elemType>::max(int x, int y) const
{
if (x >= y)
return x;
else
return y;
}
template <class elemType>
void binaryTreeType<elemType>::copyTree(binaryTreeNode<elemType>* &copiedTreeRoot,binaryTreeNode<elemType>* otherTreeRoot)
{
if (otherTreeRoot == NULL)
copiedTreeRoot = NULL;
else
{
copiedTreeRoot = new binaryTreeNode<elemType>;
copiedTreeRoot->info = otherTreeRoot->info;
copyTree(copiedTreeRoot->llink, otherTreeRoot->llink);
copyTree(copiedTreeRoot->rlink, otherTreeRoot->rlink);
}
} //end copyTree
template <class elemType>
void binaryTreeType<elemType>::destroy(binaryTreeNode<elemType>* &p)
{
if (p != NULL)
{
destroy(p->llink);
destroy(p->rlink);
delete p;
p = NULL;
}
}
template <class elemType>
void binaryTreeType<elemType>::destroyTree()
{
destroy(root);
}
template <class elemType>
binaryTreeType<elemType>::binaryTreeType(const binaryTreeType<elemType>& otherTree)
{
if (otherTree.root == NULL) //otherTree is empty
root = NULL;
else
copyTree(root, otherTree.root);
}
template <class elemType>
binaryTreeType<elemType>::~binaryTreeType()
{
destroy(root);
}
template <class elemType>
const binaryTreeType<elemType>& binaryTreeType<elemType>::operator=(const binaryTreeType<elemType>& otherTree)
{
if (this != &otherTree) //avoid self-copy
{
if (root != NULL) //if the binary tree is not empty,
//destroy the binary tree
destroy(root);
if (otherTree.root == NULL) //otherTree is empty
root = NULL;
else
copyTree(root, otherTree.root);
}//end else
return *this;
}
template <class elemType>
int binaryTreeType<elemType>::leavesCount(binaryTreeNode<elemType> *p) const
{
if(p == NULL)
return 0;
if(p->llink == NULL && p->rlink==NULL)
return 1;
else
return leavesCount(p->llink) + leavesCount(p->rlink);
}
template <class elemType>
int binaryTreeType<elemType> ::nodeCount(binaryTreeNode<elemType> *p) const
{
int count = 1;
if ( p == NULL ){
return 0;
}else{
count += nodeCount(p->llink);
count += nodeCount(p->rlink);
}
return count;
}
#endif // BINARYTREETYPE_H
bSearchTreeType.h
#ifndef BSEARCHTREETYPE_H
#define BSEARCHTREETYPE_H
#include "binaryTreeType.h"
#include <iostream>
#include <cassert>
template <class elemType>
class bSearchTreeType : public binaryTreeType<elemType>
{
public:
bool search(const elemType& searchItem) const;
//Function to determine if searchItem is in the binary
//search tree.
//Postcondition: Returns true if searchItem is found in the
// binary search tree; otherwise, returns false.
void insert(const elemType& insertItem);
//Function to insert insertItem in the binary search tree.
//Postcondition: If no node in the binary search tree has the
// same info as insertItem, a node with the info insertItem
// is created and inserted in the binary search tree.
void deleteNode(const elemType& deleteItem);
//Function to delete deleteItem from the binary search tree.
//Postcondition: If a node with the same info as deleteItem
// is found, it is deleted from the binary search tree.
protected:
binaryTreeNode<elemType> *root;
private:
void deleteFromTree(binaryTreeNode<elemType>* &p);
//Function to delete the node to which p points is deleted
//from the binary search tree.
//Postcondition: The node to which p points is deleted from
// the binary search tree.
};
using namespace std;
template <class elemType>
bool bSearchTreeType<elemType>::search(const elemType& searchItem) const
{
binaryTreeNode<elemType> *current;
bool found = false;
if (root == NULL)
cerr << "Cannot search the empty tree." << endl;
else
{
current = root;
while (current != NULL && !found)
{
if (current->info == searchItem)
found = true;
else if (current->info > searchItem)
current = current->llink;
else
current = current->rlink;
}//end while
}//end else
return found;
}//end search
template <class elemType>
void bSearchTreeType<elemType>::insert(const elemType& insertItem)
{
binaryTreeNode<elemType> *current; //pointer to traverse the tree
binaryTreeNode<elemType> *trailCurrent; //pointer behind current
binaryTreeNode<elemType> *newNode; //pointer to create the node
newNode = new binaryTreeNode<elemType>;
assert(newNode != NULL);
newNode->info = insertItem;
newNode->llink = NULL;
newNode->rlink = NULL;
if (root == NULL)
root = newNode;
else
{
current = root;
while (current != NULL)
{
trailCurrent = current;
if (current->info == insertItem)
{
std::cerr << "The insert item is already in the list-";
std::cerr << "duplicates are not allowed." << insertItem << std::endl;
return;
}
else if (current->info > insertItem)
current = current->llink;
else
current = current->rlink;
}//end while
if (trailCurrent->info > insertItem)
trailCurrent->llink = newNode;
else
trailCurrent->rlink = newNode;
}
}//end insert
template <class elemType>
void bSearchTreeType<elemType>::deleteFromTree(binaryTreeNode<elemType>* &p)
{
binaryTreeNode<elemType> *current;//pointer to traverse the tree
binaryTreeNode<elemType> *trailCurrent; //pointer behind current
binaryTreeNode<elemType> *temp; //pointer to delete the node
if (p == NULL)
cerr << "Error: The node to be deleted is NULL." << endl;
else if(p->llink == NULL && p->rlink == NULL)
{
temp = p;
p = NULL;
delete temp;
}
else if(p->llink == NULL)
{
temp = p;
p = temp->rlink;
delete temp;
}
else if(p->rlink == NULL)
{
temp = p;
p = temp->llink;
delete temp;
}
else
{
current = p->llink;
trailCurrent = NULL;
while (current->rlink != NULL)
{
trailCurrent = current;
current = current->rlink;
}//end while
p->info = current->info;
if (trailCurrent == NULL) //current did not move;
//current == p->llink; adjust p
p->llink = current->llink;
else
trailCurrent->rlink = current->llink;
delete current;
}//end else
}//end deleteFromTree
template <class elemType>
void bSearchTreeType<elemType>::deleteNode(const elemType& deleteItem)
{
binaryTreeNode<elemType> *current; //pointer to traverse the tree
binaryTreeNode<elemType> *trailCurrent; //pointer behind current
bool found = false;
if (root == NULL)
std::cout << "Cannot delete from the empty tree." << endl;
else
{
current = root;
trailCurrent = root;
while (current != NULL && !found)
{
if (current->info == deleteItem)
found = true;
else
{
trailCurrent = current;
if (current->info > deleteItem)
current = current->llink;
else
current = current->rlink;
}
}//end while
if (current == NULL)
std::cout << "The delete item is not in the tree." << endl;
else if (found)
{
if (current == root)
deleteFromTree(root);
else if (trailCurrent->info > deleteItem)
deleteFromTree(trailCurrent->llink);
else
deleteFromTree(trailCurrent->rlink);
}//end if
}
}//end deleteNode
#endif // BSEARCHTREETYPE_H
解决方案
(这是大量的代码。请删除您的测试用例下次不需要的所有内容。)
将你的代码缩减到最基本的部分,我们得到
template <class elemType>
class binaryTreeType
{
public:
bool isEmpty() const;
protected:
binaryTreeNode<elemType> *root;
};
template <class elemType>
bool binaryTreeType<elemType>::isEmpty() const
{
return (root == NULL);
};
template <class elemType>
class bSearchTreeType : public binaryTreeType<elemType>
{
void insert(const elemType& insertItem);
protected:
binaryTreeNode<elemType> *root;
};
template <class elemType>
void bSearchTreeType<elemType>::insert(const elemType& insertItem)
{
// ...
if (root == NULL)
root = newNode;
else
{
current = root;
//...
}
}//end insert
现在我们可以看到您声明了两个名为“root”的成员变量。
一个 inbSearchTreeType
隐藏一个 in binaryTreeType
- 它不是对同一变量的重新声明或“覆盖”。
这意味着您的binaryTreeType
成员函数(例如isEmpty
)使用root
in binaryTreeType
,而bSearchTreeType
(例如)的成员函数insert
使用root
in bSearchTreeType
,因此在insert
更新了一个根之后,另一个仍然为空。
顺便说一句,使用调试器也很难发现这个问题,在调试器中,您只会盯着一个变量,其值会像变魔术一样发生变化。
你需要做两件事:
- 删除
root
成员bSearchTreeType
- 因为这些是模板,所以您还需要在成员函数中更改
root
为。(找出为什么离开作为一个练习——这是一篇自己的文章。)this->root
bSearchTreeType
(顺便说一句,它似乎只适用于这些更改。做得好。)
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