【发布时间】：2014-04-03 16:38:23
【问题描述】：
所以我一直在研究这个自平衡 AVL 树，我觉得它工作正常，但是有一些内存泄漏。我已经搜索并经历了一百万次，感觉就像试图弄清楚我做错了什么，但我对整个内存泄漏的事情还是新手，显然需要了解更多。如果有人可以帮助我或者可以看到泄漏的位置可能很棒，这里是我的 AVL 树的代码：
#pragma once
#include <algorithm>
#include <fstream>
#include "LinkedList.h"
template <typename ItemType>
class AVLTreeSet {
private:
struct Node {
ItemType info;
Node* left;
Node* right;
int height;
};
Node* root;
int size;
public:
AVLTreeSet()
{
root = NULL;
size = 0;
}
~AVLTreeSet()
{
clear();
}
void clear()
{
Node* n = root;
if(n != NULL)
{
clearTree(n->left);
clearTree(n->right);
delete n;
}
root = NULL;
}
void clearTree(Node* n)
{
if(n != NULL)
{
clearTree(n->left);
clearTree(n->right);
delete n;
}
}
void print(std::ofstream &out)
{
//cout << "HERE" << endl;
LinkedList<Node*> list;
int level = 0;
int levelSize;
int count = 0;
Node* n = root;
if (n == NULL)
{
return;
}
list.insert(n);
levelSize = list.getSize();
while(list.getSize() != 0)
{
count = 0;
out << "level " << level << ": ";
for (unsigned i = levelSize; i > 0; i--)
{
count++;
if (count > 8)
{
out << std::endl;
out << "level " << level << ": ";
count = 0;
}
n = list.getInfo();
out <<n->info << "(" << getHeight(n) << ") ";
if (n->left != NULL)
{
//cout << "left is not null" << endl;
list.insert(n->left);
}
if (n->right != NULL)
{
list.insert(n->right);
//cout << "right is not null" << endl;
}
list.remove();
}
levelSize = list.getSize();
level++;
out << std::endl;
//levelSize = list.getSize();
}
}
void insert(const ItemType& item)
{
//cout << "Insert FUNCTION" << endl;
Node* current = root;
if (current == NULL)
{
//cout << "ADD FUNCTION NULL" << endl;
current = new Node;
current->info = item;
current->left = NULL;
current->right = NULL;
current->height = 0;
root = current;
size++;
//cout << current->info << endl;
//cout << current->height << endl;
return;
}
if (current->info > item)
{
current->left = add(item, current->left);
}
if (current->info < item)
{
current->right = add(item, current->right);
}
current = balance(current);
root = current;
}
Node* add(const ItemType& item, Node* current)
{
if (current == NULL)
{
current = new Node;
current->info = item;
current->left = NULL;
current->right = NULL;
current->height = 0;
size++;
}
if (current->info > item)
{
current->left = add(item, current->left);
}
if (current->info < item)
{
current->right = add(item, current->right);
}
return current;
}
void remove(const ItemType& item)
{
Node* current = root;
if (current == NULL)
{
//cout << "NULL" << endl;
return;
}
if (current->info == item)
{
//cout << "FOUND" << endl;
current = removeNext(item, current);
current = balance(current);
root = current;
return;
}
if (current->info > item)
{
//cout << "LEFT" << endl;
current->left = removeNext(item, current->left);
if (current == root)
{
root = balance(current);
}
return;
}
if (current->info < item)
{
//cout << "RIGHT" << endl;
current->right = removeNext(item, current->right);
if (current == root)
{
root = balance(current);
}
return;
}
}
Node* removeNext(const ItemType& item, Node* current)
{
Node* temp;
if (current != NULL)
{
if (current->info > item)
{
//cout << "REMOVENEXT LEFT" << endl;
current->left = removeNext(item, current->left);
return current;
}
if (current->info < item)
{
//cout << "REMOVENEXT RIGHT" << endl;
current->right = removeNext(item, current->right);
return current;
}
//cout << "FOUND" << endl;
if (current->left != NULL && current->right != NULL)
{
//cout << "LEFT AND RIGHT CHILDREN" << endl;
temp = current;
current = CTR(current->right);
current->left = temp->left;
//cout << current->info << endl;
//looker = removeNext(current->info, temp->right);
delete temp;
size--;
current = balance(current);
return current;
}
else if (current->right != NULL)
{
//cout << "RIGHT ONE CHILD" << endl;
temp = current;
current = current->right;
delete temp;
size--;
current = balance(current);
return current;
}
else if (current->left != NULL)
{
//cout << "LEFT ONE CHILD" << endl;
temp = current;
current = current->left;
delete temp;
size--;
current = balance(current);
return current;
}
//cout << "CURRENT NODE" << endl;
delete current;
size--;
return NULL;
}
//cout << "NOT FOUND" << endl;
return current;
}
Node* CTR(Node* current)
{
while(current->left != NULL)
{
//cout << "ENTERED LOOP" << endl;
current = current->left;
}
//cout << current->info << endl;
return current;
}
bool find(const ItemType& item)
{
Node* current = root;
bool find = false;
if (current == NULL)
{
return find;
}
if (item == current->info)
{
find = true;
return find;
}
if (current->info > item && current->left != NULL)
{
find = findLeft(item, current->left);
}
if (current->info < item && current->right != NULL)
{
find = findRight(item, current->right);
}
return find;
}
bool findLeft(const ItemType& item, Node* current)
{
bool find = false;
if (item == current->info)
{
find = true;
return find;
}
if (current->info > item && current->left != NULL)
{
find = findLeft(item, current->left);
}
if (current->info < item && current->right != NULL)
{
find = findRight(item, current->right);
}
return find;
}
bool findRight(const ItemType& item, Node* current)
{
bool find = false;
if (item == current->info)
{
find = true;
return find;
}
if (current->info > item && current->left != NULL)
{
find = findLeft(item, current->left);
}
if (current->info < item && current->right != NULL)
{
find = findRight(item, current->right);
}
return find;
}
int getHeight(Node* temp)
{
int h = 0;
if (temp != NULL)
{
int l_height = getHeight(temp->left);
int r_height = getHeight(temp->right);
int max_height = std::max(l_height, r_height);
h = max_height + 1;
}
return h;
}
void setHeight(Node* n)
{
n->height = std::max(getHeight(n->right), getHeight(n->left)) + 1;
}
Node* balance(Node* n)
{
if (size == 1)
{
return n;
}
else if(getHeight(n->left) - getHeight(n->right) > 1) //n is out of balance
{
//cout << "BALANCE RIGHT" << endl;
n = balanceToRight(n);
}
else if(getHeight(n->right) - getHeight(n->left) > 1)
{
//cout << "BALANCE LEFT" << endl;
n = balanceToLeft(n);
}
return n;
}
Node* balanceToRight(Node* n)
{
if(getHeight(n->left->right) > getHeight(n->left->left))
{
n->left = rotateLeft(n->left); //<--- extra step for double rotate
}
n = rotateRight(n); //<--- this is for single
return n;
}
Node* balanceToLeft(Node* n)
{
if(getHeight(n->right->left) > getHeight(n->right->right))
{
n->right = rotateRight(n->right); //<--- extra step for double rotate
}
n = rotateLeft(n); //<--- this is for single
return n;
}
Node* rotateRight(Node* n)
{
Node* temp = n->left;
n->left = temp->right;
temp->right = n;
setHeight(n); //<--- set first
setHeight(temp);
return temp;
}
Node* rotateLeft(Node* n)
{
Node* temp = n->right;
n->right = temp->left;
temp->left = n;
setHeight(n); //<--- set first
setHeight(temp);
return temp;
}
};
我通过读取我的 main.cpp 文件来运行程序，该文件调用我的 AVLtree 的命令。我知道它有很多代码，但我很紧张，因为我找不到它可能发生的地方。谢谢。
【问题讨论】：
-
你试过通过valgrind-memcheck运行它吗？
-
您有泄漏，因为您手动调用
new和delete。不要那么做。你是一棵简单的有向树。将子Node*替换为std::unique_ptr<Node>，在需要时执行move，那么我敢说你有泄漏。您可能必须编写templare<typename T, typename...Args>std::unique_ptr<T> make_unique(Args&&...args)才能从客户端代码中删除new，但这可能有点矫枉过正：在您的情况下，您不需要处理任意 ctor。 -
是否有特定的命令序列导致您检测到泄漏？
-
你怎么知道有内存泄漏？你检查过你的
LinkedList实现了吗？当我使用_CrtDumpMemoryLeaks在 Visual Studio 中运行它（并实例化一棵树，插入单个元素）时，我没有看到任何泄漏。
标签： c++ memory-leaks avl-tree