平衡二叉树最全代码

#include<stdio.h>
#include<stdlib.h>

typedef struct Node
{
	int val;
	int height;
	struct Node *left;
	struct Node *right;
}Node;

//创建新结点
Node* newNode(int val)
{
	Node *node = (Node*)malloc(sizeof(Node));
	node->val = val;
	node->height = 1;
	node->left = node->right = NULL;
	return node;
}

//获取结点高度
int getHeight(Node *node)
{
	return node ? node->height : 0;
}

int max(int a,int b)
{
	return a>b?a:b;
}

//左旋操作
Node* leftRotate(Node* root)
{
	Node *newRoot = root->right;
	Node *T2 = newRoot->left;
	newRoot->left = root;
	root->right = T2;
	root->height = max(getHeight(root->left),getHeight(root->right)) + 1;
	newRoot->height = max(getHeight(newRoot->left),getHeight(newRoot->right)) + 1;
	return newRoot;
}

//右旋操作
Node* rightRotate(Node* root)
{
	Node *newRoot = root->left;
	Node *T2 = newRoot->right;
	newRoot->right = root;
	root->height = max(getHeight(root->left),getHeight(root->right)) + 1;
	root->height = max(getHeight(newRoot->left),getHeight(newRoot->right)) + 1;
	return newRoot;
}

//获取平衡因子(BF)
int getBalance(Node *node)
{
	return getHeight(node->left) - getHeight(node->right);
}

//插入结点
Node* insert(Node* node,int key)
{
	if(!node)
		return newNode(key);
	if(key < node->val)
		node->left = insert(node->left,key);
	else if(key > node->val)
		node->right = insert(node->right,key);
	else 
		return node;
	node->height = 1 + max(getHeight(node->left),getHeight(node->right));
	int balance = getBalance(node);
	// 左左情况
	if(balance > 1 && getBalance(node->left) > 0)
		return rightRotate(node);
	//右右情况
	if(balance < -1 && getBalance(node->right) < 0)
		return leftRotate(node);
	//左右情况	
	if(balance > 1 && getBalance(node->left) < 0)
	{
		node->left = leftRotate(node->left);
		return rightRotate(node);
	}
	//右左情况
	if(balance < -1 && getBalance(node->right) > 0)  
	{
		node->right =  rightRotate(node->right);
		return  leftRotate(node);
	}
	return node;
}

//删除结点
Node* deleteNode(Node* root,int key)
{
	if(!root)
		return root;
	if(key<root->val)
		root->left = deleteNode(root->left,key);
	else if(key>root->val)
		root->right = deleteNode(root->right,key);
	else
	{
		if(root->left == NULL || root->right == NULL)
		{
			Node *temp = root->left ? root->left : root->right;
			if(temp == NULL)
			{
				temp = root;
				root = NULL;
			}
			else
			{
				*root =  *temp;
			}
			free(temp);
		}
		else
		{
			Node *temp = root->right;
			while(temp && temp->left != NULL)
				temp = temp->left;
			root->val = temp->val;
			root->right = deleteNode(root->right,temp->val);
		}
	}
	if(root == NULL)
		return root;
	root->height = 1 + max(getHeight(root->left),getHeight(root->right));
	int balance =getBalance(root);
	if(balance > 1 && getBalance(root->left) >= 0)
		return rightRotate(root);
	if(balance > 1 && getBalance(root->left) < 0)
	{
		root->left = leftRotate(root->left);
		return rightRotate(root);
	}
	if(balance < -1 && getBalance(root->right) <= 0)
		return leftRotate(root);
	if(balance < -1 && getBalance(root->right) > 0)
	{
		root->right = rightRotate(root->right);
		return leftRotate(root);
	}
	return root;
}
// 修改节点值
Node* modifyNode(Node* root, int oldVal, int newVal) {
    // 先删除节点
    root = deleteNode(root, oldVal);

    // 然后插入新的值
    root = insert(root, newVal);

    return root;  // 返回修改后的树的根
}
void preOrder(Node *root)
{
	if(root)
	{
		printf("%d ",root->val);
		preOrder(root->left);
		preOrder(root->right);
	}
}

void inOrder(Node *root)
{
	if(root)
	{
		inOrder(root->left);
		printf("%d ",root->val);
		inOrder(root->right);
	}
}

Node *find(Node *root,int key)
{
	if(root == NULL || root->val)
		return root;
	if(key < root->val)
		return find(root->left,key);
	else
		return find(root->right,key);
}

void test()
{
	 // 插入节点
	 Node *root = NULL;
    root = insert(root, 10);
    root = insert(root, 20);
    root = insert(root, 30);
    root = insert(root, 40);
    root = insert(root, 50);
    root = insert(root, 60);
    root = insert(root, 70);
    root = insert(root, 80);
    printf("-----先序遍历-----\n");
    preOrder(root);
    printf("\n");

    printf("-----中序遍历-----\n");
    inOrder(root);
    printf("\n");

	
    // 修改节点
    
    printf("修改节点 30 为 35:\n");
    root = modifyNode(root, 30, 35);
    printf("-----先序遍历-----\n");
    preOrder(root);
    printf("\n");
   	printf("删除节点35:\n");
    root = deleteNode(root, 35);
    preOrder(root);
    printf("\n");
    
}


int main()
{
	test();
	return 0;
}