AVL Tree

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

struct node
{
	int data;
	struct node *left,*right;
	int height;
};
int height(struct node *root)
{
	if(root)
		return root->height;
	return -1;
}
int max(int a, int b)
{
	return a>b?a:b;
}
void setHeight(struct node *root)
{
	root->height=max(height(root->left),height(root->right))+1;
}
struct node * rotateLeft(struct node *root)
{
	//printf("rotateLeft := %d\n",root->data);
	struct node *newroot = root->left;
	root->left=newroot->right;
	newroot->right=root;
	setHeight(newroot);
	setHeight(root);
	return newroot;
}
struct node * rotateRight(struct node *root)
{
	//printf("rotateRight := %d\n",root->data);
	struct node *newroot=root->right;
	root->right=newroot->left;
	newroot->left=root;
	setHeight(newroot);
	setHeight(root);
	return newroot;
}
struct node * doubleRotateLeft(struct node *root)
{
	//printf("doubleRotateLeft := %d\n",root->data);
	root->left = rotateRight(root->left);
	return rotateLeft(root);
}
struct node * doubleRotateRight(struct node *root)
{
	//printf("doubleRotateRight := %d\n",root->data);
	root->right =rotateLeft(root->right);
	return rotateRight(root);
}
struct node *newNode(int data)
{
	struct node *temp = (struct node*)malloc(sizeof(struct node));
	temp->data=data;
	temp->left=temp->right=NULL;
	temp->height=0;
	return temp;
}
struct node * insert(struct node *root, int data)
{
	if(root == NULL)
	{
		root = newNode(data);
	}
	else if(data<root->data)
	{
		root->left= insert(root->left,data);
		if(height(root->left)-height(root->right)==2)
		{
			//printf("\t** while insert %d** \n",data);
			if(data<root->left->data)
				root =  rotateLeft(root);
			else
				root = doubleRotateLeft(root);
		}
	}
	else if(data > root->data)
	{
		root->right= insert(root->right,data);
		if(height(root->right)-height(root->left)==2)
		{
			//printf("\t** while insert %d** \n",data);
			if(data > root->right->data)
				root = rotateRight(root);
			else
				root = doubleRotateRight(root);
		}
	}
	setHeight(root);
	return root;
}
void preOrder(struct node *root)
{
	if(root != NULL)
	{
		printf("%d\n",root->data);
		preOrder(root->left);
		preOrder(root->right);
	}
}

void postOrder(struct node *root)
{
	if(root != NULL)
	{
		postOrder(root->left);
		postOrder(root->right);
		printf("%d\n",root->data);
	}
}

void main()
{
	struct node *root = NULL;
	root = insert(root,60);
	root = insert(root,80);
	root = insert(root,65);
	root = insert(root,90);
	root = insert(root,100);
	root = insert(root,70);
	root = insert(root,20);
	root = insert(root,30);
	root = insert(root,35);
	printf("\t**Pre Order**\n");
	preOrder(root);
	printf("\t**Post Order**\n");
	postOrder(root);
}