tree1.c

#include<stdio.h> 
#include<stdlib.h> 
struct node 
{ 
	int data; 
	struct node *left; 
	struct node *right; 
}; 

/* newNode() allocates a new node with the given data and NULL left and 
right pointers. */
struct node* newNode(int data) 
{ 
// Allocate memory for new node 
struct node* node = (struct node*)malloc(sizeof(struct node)); 

// Assign data to this node 
node->data = data; 

// Initialize left and right children as NULL 
node->left = NULL; 
node->right = NULL; 
return(node); 
} 


int main() 
{ 
/*create root*/
struct node *root = newNode(1); 
/* following is the tree after above statement 

		1 
	/ \ 
	NULL NULL 
*/


root->left	 = newNode(2); 
root->right	 = newNode(3); 
/* 2 and 3 become left and right children of 1 
		1 
		/ \ 
		2	 3 
	/ \ / \ 
	NULL NULL NULL NULL 
*/


root->left->left = newNode(4); 
/* 4 becomes left child of 2 
		1 
	/	 \ 
	2		 3 
	/ \	 / \ 
4 NULL NULL NULL 
/ \ 
NULL NULL 
*/

getchar(); 
return 0; 
}