我正在开发一个AVL二叉树实现，除了我的旋转和删除功能之外，我的大部分代码都在工作。我尝试了不同的实现方法，但我仍然无法弄清楚我做错了什么。如果有人可以帮助我解决方案，将不胜感激。如果我注释掉平衡功能，代码将根据需要工作并插入导入的文本文件中的所有单词，但是当我尝试平衡代码爆炸的节点时。由于某些原因，我的问题出现了：
删除节点;
我的代码部分，但我不确定为什么会出现这个问题。通过树的递归没有问题但是一旦它到达删除节点部分它就有问题，这对我没有意义......
头：
#ifndef AVLBINARYTREE_H
#define AVLBINARYTREE_H
#include <iostream>
#include <string>
using namespace std;
class LinkedBinaryTree {
private:
struct Node {
string word;
Node* left;
Node* right;
Node* parent;
int wordCount;
int height;
Node() : word(), left(NULL), right(NULL), parent(NULL), wordCount(1), height(0) {}
Node(string s, Node* l, Node* r, Node* p) {
word = s;
left = NULL;
right = NULL;
parent = p;
wordCount = 1;
height = 0;
}
};
Node* _root;
public:
LinkedBinaryTree();
~LinkedBinaryTree();
void destroyTree();
void destroyTree(Node* node);
void insert(string word);
void display(Node* ptr, int level);
Node* root();
void inOrder(Node* node);
int avlNum(Node* node);
int getNumWords();
void insertNode(Node* node, string word);
int height(Node* node);
int bfactor(Node* node);
void fixHeight(Node* node);
void balance(Node* node);
void rightRotate(Node* node);
void leftRotate(Node* node);
void rightLeftRotate(Node* node);
void leftRightRotate(Node* node);
int n;
};
#endif
的.cpp：
#include "AVLBinaryTree.h"
#include <algorithm>
void LinkedBinaryTree::inOrder(Node* node) {
if (node == NULL)
return;
inOrder(node->left);
cout << node->wordCount << " " << node->word << endl;
inOrder(node->right);
}
void LinkedBinaryTree::rightRotate(Node* node) {
Node* temp;
temp = node->left;
node->left = temp->right;
//node->left->parent = node;
temp->parent = node->parent;
temp->right = node;
node->parent = temp;
node = temp;
if (temp->parent == NULL) {
_root = node;
}
fixHeight(node);
fixHeight(node->right);
fixHeight(node->left);
}
void LinkedBinaryTree::leftRotate(Node* node) {
Node* temp;
temp = node->right;
node->right = temp->left;
temp->parent = node->parent;
temp->left = node;
node->parent = temp;
node = temp;
if (temp->parent == NULL) {
_root = node;
}
fixHeight(node);
fixHeight(node->right);
fixHeight(node->left);
}
void LinkedBinaryTree::rightLeftRotate(Node* node) {
rightRotate(node->left);
leftRotate(node);
}
void LinkedBinaryTree::leftRightRotate(Node* node) {
leftRotate(node->right);
rightRotate(node);
}
int LinkedBinaryTree::height(Node* node) {
int h = 0;
if (node != NULL) {
h = node->height;
}
return h;
}
int LinkedBinaryTree::bfactor(Node* node) {
return height(node->right) - height(node->left);
}
void LinkedBinaryTree::fixHeight(Node* node) {
int hl = height(node->left);
int hr = height(node->right);
node->height = (hl > hr ? hl : hr) + 1;
}
int LinkedBinaryTree::avlNum(Node* node) {
int leftH = height(node->left);
int rightH = height(node->right);
int avlNum = rightH - leftH;
return avlNum;
}
LinkedBinaryTree::LinkedBinaryTree() {
_root = NULL;
}
LinkedBinaryTree::~LinkedBinaryTree() {
destroyTree();
}
void LinkedBinaryTree::destroyTree() {
destroyTree(_root);
}
//**********************************************************
// destroyTree is called by the destructor. It deletes
// all nodes in the tree.
//**********************************************************
void LinkedBinaryTree::destroyTree(Node* node) {
if (node != NULL) {
if (node->left != NULL)
destroyTree(node->left);
if (node->right != NULL)
destroyTree(node->right);
delete node;
}
}
void LinkedBinaryTree::insertNode(Node* node, string word) {
if (word < node->word) {
if (node->left != NULL)
insertNode(node->left, word);
else {
node->left = new Node(word, NULL, NULL, node);
n++;
fixHeight(node->left);
}
}
else if (word > node->word) {
if (node->right != NULL)
insertNode(node->right, word);
else {
node->right = new Node(word, NULL, NULL, node);
n++;
fixHeight(node->right);
}
}
else if (word == node->word) {
node->wordCount++;
}
balance(node);
}
void LinkedBinaryTree::insert(string word) {
if (_root == NULL) {
_root = new Node(word, NULL, NULL, NULL);
n++;
}
else {
insertNode(_root, word);
}
}
void LinkedBinaryTree::display(Node* ptr, int level) {
int i;
if (ptr != NULL)
{
display(ptr->right, level + 1);
printf("\n");
if (ptr == _root)
cout << "Root -> ";
for (i = 0; i < level && ptr != _root; i++)
cout << " ";
cout << ptr->word;
display(ptr->left, level + 1);
}
}
LinkedBinaryTree::Node * LinkedBinaryTree::root() {
return _root;
}
void LinkedBinaryTree::balance(Node* node) {
fixHeight(node);
if (bfactor(node) == 2) {
if (bfactor(node->right) < 0)
rightRotate(node->right);
else
leftRotate(node);
}
if (bfactor(node) == -2) {
if (bfactor(node->left) > 0)
leftRotate(node->left);
else
rightRotate(node);
}
}
int LinkedBinaryTree::getNumWords() {
return n;
}
主：
#include "AVLBinaryTree.h"
#include <iostream>
#include <fstream>
#include <string>
#include <queue>
#include <vector>
#include <functional>
int main(int argv, char *argc[]) {
LinkedBinaryTree t;
string word("Test."), lastword("");
for (int i = 0; i < argv; i++)
cout << argc[i] << endl;
if (argv < 2) {
cerr << "No input file specified" << endl;
system("pause");
exit(1);
}
for (int count = 1; count < argv; count++)
{
ifstream input(argc[count]);
if (!input) {
cerr << "Cannot open input file" << argc[count] << endl;
system("pause");
exit(1);
}
while (input >> word)
{
transform(word.begin(), word.end(), word.begin(), ::tolower);
word.erase(remove_if(word.begin(), word.end(), ispunct));
t.insert(word);
}
}
t.inOrder(t.root());
cout << endl;
cout << "--------" << endl;
cout << t.getNumWords() << " " << "Total number of different words";
cout << endl;
/*t.insert("Yes");
t.insert("No");
t.insert("Maybe");
t.insert("Hopefully");
t.insert("Absolutely");
t.display(t.root(), 1);
cout << endl;
cout << endl;
t.inOrder(t.root());
*/
system("PAUSE");
t.~LinkedBinaryTree();
return EXIT_SUCCESS;
}
提前感谢！
答案 0 :(得分：1)
旋转函数中的node = temp;行正在更改属于该函数的指针的本地值，不存储在树中的值。例如，当您拨打rightRotate(node->right)时，node->right的值在呼叫后应该更新时是相同的。
可能的解决方案包括将节点指针作为引用（void LinkedBinaryTree::rightRotate(Node*& node)）传递给rotate函数，以便更新原始值，或返回更新的值（Node *LinkedBinaryTree::rightRotate(Node* node)）并适当地存储它。
您的balance功能和其他旋转功能可能同样受到影响。