BSTSEARC.C

#include<stdio.h>
#include<conio.h>
#include<alloc.h>

typedef struct treeNode* treePointer;

struct treeNode
{
	int data;
	treePointer leftChild,rightChild;
};

treePointer root=NULL;

void create();
void search(int);

void main()
{
	int choice,n;
	do
	{
		clrscr();
		printf("\n\tBINARY SEARCH TREE OPERATIONS\n");
		printf("\n\t\t1. Create");
		printf("\n\t\t2. Search");
		printf("\n\t\t3. Exit");
		printf("\n\n\tEnter your choice(1-3) : ");
		scanf("%d",&choice);
		switch(choice)
		{
			case 1:
				create();
				break;
			case 2:
				if(root==NULL) printf("\nTree is empty...");
				else
				{
					printf("\nEnter the element : ");
					scanf("%d",&n);
					search(n);
				}
				break;
			default:continue;
		}
		getch();
	}while(choice!=3);
}

void create()
{
	int i,n=0,left;
	treePointer node,temp,p;
	if(root!=NULL)
	{
		printf("\nTree already exists...");
		return;
	}
	printf("\nEnter the number of nodes : ");
	scanf("%d",&n);
	printf("\nEnter %d nodes for the binary search tree:\n",n);
	root=(treePointer)malloc(sizeof(*root));
	scanf("%d",&root->data);
	root->leftChild=root->rightChild=NULL;
	for(i=0;i<n-1;i++)
	{
		temp=(treePointer)malloc(sizeof(*temp));
		scanf("%d",&temp->data);
		temp->leftChild=temp->rightChild=NULL;
		node=root;
		while(node!=NULL)
		{
			left=0;
			p=node;
			if(temp->data<node->data)
			{
				left=1;
				node=node->leftChild;
			}
			else node=node->rightChild;
		}
		if(left) p->leftChild=temp;
		else p->rightChild=temp;
	}
	printf("\n\nBinary search tree created with %d nodes...",n);
}
void search(int x)
{
	treePointer node;
	node=root;
	while(node!=NULL)
	{
		if(node->data==x)
		{
			printf("\nElement is found");
			return;
		}
		if(x<node->data) node=node->leftChild;
		else node=node->rightChild;
	}
	printf("\nElement is not found");
}