C++ stack问题

[shuaiwang_01]

#include <iostream>
#include <stack>
using namespace std;

class Node
{
public:
	char* data;
	Node* left;
	Node* right;
	int balance;
	int count;
	Node()
	{
		data = NULL;
		left = right = NULL;
		balance = count = 0;
	}
	Node(char* s)
	{
		data = new char[30];
		int i;
		for(i = 0; i < strlen(data); i++)
			data[i] = s[i];
		data[i] = '\0';
		left = NULL;
		right = NULL;
		balance = 0;
		count = 1;
	}
};


class AVLTree
{
private:
	Node* root;
	
public:
	int vertexNumber;
	AVLTree()
	{
		root = NULL;
		vertexNumber = 0;
	}

	
	AVLTree(Node* r)
	{
		root = r;
	}
	int depth(Node* node)
	{
		if(node == NULL)
			return -1;
		int l = depth(node->left);
		int r = depth(node->right);

		return (l < r)?(r+1):(l+1);
	}

	void insert(char* &str)
	{
		Node* child = root;
		Node* parent = NULL;
		Node* grandpa = NULL;
		int flag;
		stack<Node* > st;
		
		if(root == NULL)
		{
			Node* no = new Node(str);
			root = no;
			return;
		}
		
		while(child != NULL)
		{
			if(strcmp(str, child->data) == 0)
			{
				(child->count)++;
				delete str;
				return;
			}

			parent = child;
			st.push(parent);
			if(strcmp(str, child->data) < 0)
				child = parent->left;
			else
				child = parent->right;
		}
		Node* node = new Node(str);
		if(strcmp(node->data, parent->data) < 0)
			parent->left = node;
		else 
			parent->right = node;

		while(!st.empty())
		{
			parent = st.top();
			st.pop();
			if(parent->left == node)
				parent->balance += 1;
			else 
				parent->balance -= 1;

			if(parent->balance == 0)
				break;
			else if(parent->balance == -1 || parent->balance == 1)
				node = parent;
			else
			{
				flag = (parent->balance < 0)? -1 : 1;
				if(node->balance == flag)
				{
					if(flag == -1)
						leftRotate(parent);
					else
						rightRotate(parent);
				}
				else
				{
					if(parent->balance == -2)
						rightLeftRotate(parent);
					else
						leftRightRotate(parent);
				}
				break;
			}
		}

		if(st.empty())
			root = parent;
		else
		{
			grandpa = st.top();
			if(grandpa->data > parent->data)
				grandpa->left = parent;
			else
				grandpa->right = parent;
		}
	}

	void leftRotate(Node* &node)
	{
		Node* temp = node;
		node = node->right;
		temp->right = node->left;
		node->left = temp;
		temp->balance = node->balance = 0;
	}

	void rightRotate(Node* &node)
	{
		Node* temp = node;
		node = node->left;
		temp->left = node->right;
		node->right = temp;
		temp->balance = node->balance = 0;
	}

	void leftRightRotate(Node* &node)
	{
		Node* rightChild = node;
		Node* leftChild = node->left;

		node = leftChild->right;
		leftChild->right = node->left;
		node->left = leftChild;

		if(node->balance <0 )
			leftChild->balance = 1;
		else
			leftChild->balance = 0;

		rightChild->left = node->right;
		node->right = rightChild;

		if(node->balance <=0)
			rightChild->balance = 0;
		else
			rightChild->balance = -1;

		node->balance = 0;
	}

	void rightLeftRotate(Node* &node)
	{
		Node* leftChild = node;
		Node* rightChild = node->right;

		node = rightChild->left;
		rightChild->left = node->right;
		node->right = rightChild;

		if(node->balance <= 0 )
			rightChild->balance = 0;
		else
			rightChild->balance = -1;

		leftChild->right = node->left;
		node->left = leftChild;

		if(node->balance <0)
			leftChild->balance = 1;
		else
			leftChild->balance = 0;

		node->balance = 0;
	}

	void print(Node* node)
	{
		if(node == NULL)
			return;
		print(node->left);
		printf("%s %.4f\n", node->data, (double)(node->count)*100/vertexNumber);
		print(node->right);
	}

	Node* getRoot()
	{
		return root;
	}
};

int main()
{
	AVLTree* avlTree = new AVLTree();

	char* str = new char[30];
	int i = 0;
	while(gets(str) != NULL)
	{
		avlTree->insert(str);
		(avlTree->vertexNumber)++;

		if(++i == 12)
			break;
	}
	avlTree->print(avlTree->getRoot());
	return 0;
}

请大家帮我看一看，这里是输入字符串，当我运行时，输入到第三个字符串时，程序就不响应了。

然后我在main函数的

avlTree->insert(str);

处设置断点，并在每次运行时进入这个函数，但等到第三个插入时，便发现insert函数的stack<Node* > st;这里报错，说是什么堆被破坏了，我在别的程序里测试stack，用的都挺好的，在这里就出问题了，而且莫名其妙。

[shuaiwang_01]

大家不用看程序的其他部分，在输入时，请总是输入相同的字符串。然后调试insert函数，由于字符串相同，所以只会执行insert函数的前几句。

[LinuxBirdMan]

自己调试吧。。一步步跟踪。。这样才有进步

[look_back]

看的我头晕，不过你就设那个断点能做什么？

[dooX8086]

看了遍有两个疑问
一

    Node(char* s)
    {
        data = new char[30];
        int i;
        for(i = 0; i < strlen(data); i++) // 这样输入方式感觉很怪
            data[i] = s[i];    //一不小心 s[] 就越界了,且copy一些无用数据给 data

二. 只见 new 没看到有 delete 操作

// 用到 C 的库,都好还是 #include 相关的库

[愤怒的熊猫007]

[Quote=引用 4 楼 doox8086 的回复:]
看了遍有两个疑问
一

C/C++ code

Node(char* s)
{
data = new char[30];
int i;
for(i = 0; i < strlen(data); i++) // 这样输入方式感觉很怪
data[i] = s[i]; //一不小心 s[] ……
[/Quote]
strlen(data)该为strlen(s)？？

[大头猫]

写的程序太昏了，给点注释，错了也好找。。