binary search tree

code 1

//BINARAY SEARCH TREE
#include<iostream>
#include<conio.h>
using namespace std;
struct node
{
int info;
struct node *left, *right;
}*root=NULL,*nptr;

int insert (node *r,node *n)
{
if(root==NULL)
{
root=n;
root->left=NULL;
root->right=NULL;
return 0;
}
if(r->info==n->info)
{
cout<<"tree";
return 0;
}
if(r->info>n->info)
{
if(r->left!=NULL)
{
insert(r->left,n);
}
else
{
r->left=n;
(r->left)->left=NULL;
(r->left)->right=NULL;
}
return 0;
    }
    else
    {
    if(r->right!=NULL)
    {
    insert(r->right,n);
}
else
{
r->right=n;
(r->right)->right=NULL;
(r->right)->left=NULL;
}
return 0;
}
//PRE ORDER
}
int pre(node *p)
{
if(root==NULL)
{
cout<<"Tree is NULL\n";
return 0;
}
if(p!=NULL)
{
cout<<p->info<<endl;
pre(p->left);
pre(p->right);
}
}
//POST ORDER
int post(node *p)
{
if(root==NULL)
{
cout<<"Tree is empty\n";
return 0;
}
if(p!=NULL)
{
post(p->left);
post(p->right);
cout<<p->info<<endl;
}
}
//IN ORDER
int in(node *p)
{
if(root==NULL)
{
cout<<"Tree is empty\n";
return 0;
}
if(p!=NULL)
{
post(p->left);
cout<<p->info<<endl;
post(p->right);
}
}

int main()
{
int n;
for(int i=0;i<5;i++)
{
cout<<"Enter the Choice\n";

    cin>>n;
do
{
if(n==1)
{
nptr=new node;
       cin>>nptr->info;
       insert(root,nptr);
}
else if(n==2)
{
cout<<"PRE ORDER\n";
       pre(root);
}
else
{
cout<<"IN ORDER\n";
           in(root);
}
}
while(ch=1||2||3);
}
}
}
code 2:

# include <stdio.h>

# include <conio.h>

# include <stdlib.h>

 

typedef struct BST {

   int data;

   struct BST *lchild, *rchild;

} node;

 

void insert(node *, node *);

void inorder(node *);

void preorder(node *);

void postorder(node *);

node *search(node *, int, node **);

 

void main() {

   int choice;

   char ans = 'N';

   int key;

   node *new_node, *root, *tmp, *parent;

   node *get_node();

   root = NULL;

   clrscr();

 

   printf("\nProgram For Binary Search Tree ");

   do {

      printf("\n1.Create");

      printf("\n2.Search");

      printf("\n3.Recursive Traversals");

      printf("\n4.Exit");

      printf("\nEnter your choice :");

      scanf("%d", &choice);

 

      switch (choice) {

      case 1:

         do {

            new_node = get_node();

            printf("\nEnter The Element ");

            scanf("%d", &new_node->data);

 

            if (root == NULL) /* Tree is not Created */

               root = new_node;

            else

               insert(root, new_node);

 

            printf("\nWant To enter More Elements?(y/n)");

            ans = getch();

         } while (ans == 'y');

         break;

 

      case 2:

         printf("\nEnter Element to be searched :");

         scanf("%d", &key);

 

         tmp = search(root, key, &parent);

         printf("\nParent of node %d is %d", tmp->data, parent->data);

         break;

 

      case 3:

         if (root == NULL)

            printf("Tree Is Not Created");

         else {

            printf("\nThe Inorder display : ");

            inorder(root);

            printf("\nThe Preorder display : ");

            preorder(root);

            printf("\nThe Postorder display : ");

            postorder(root);

         }

         break;

      }

   } while (choice != 4);

}

/*

Get new Node

*/

node *get_node() {

   node *temp;

   temp = (node *) malloc(sizeof(node));

   temp->lchild = NULL;

   temp->rchild = NULL;

   return temp;

}

/*

This function is for creating a binary search tree

*/

void insert(node *root, node *new_node) {

   if (new_node->data < root->data) {

      if (root->lchild == NULL)

         root->lchild = new_node;

      else

         insert(root->lchild, new_node);

   }

 

   if (new_node->data > root->data) {

      if (root->rchild == NULL)

         root->rchild = new_node;

      else

         insert(root->rchild, new_node);

   }

}

/*

This function is for searching the node from

binary Search Tree

*/

node *search(node *root, int key, node **parent) {

   node *temp;

   temp = root;

   while (temp != NULL) {

      if (temp->data == key) {

         printf("\nThe %d Element is Present", temp->data);

         return temp;

      }

      *parent = temp;

 

      if (temp->data > key)

         temp = temp->lchild;

      else

         temp = temp->rchild;

   }

   return NULL;

}

/*

This function displays the tree in inorder fashion

*/

void inorder(node *temp) {

   if (temp != NULL) {

      inorder(temp->lchild);

      printf("%d", temp->data);

      inorder(temp->rchild);

   }

}

/*

This function displays the tree in preorder fashion

*/

void preorder(node *temp) {

   if (temp != NULL) {

      printf("%d", temp->data);

      preorder(temp->lchild);

      preorder(temp->rchild);

   }

}

 

/*

This function displays the tree in postorder fashion

*/

void postorder(node *temp) {

   if (temp != NULL) {

      postorder(temp->lchild);

      postorder(temp->rchild);

      printf("%d", temp->data);

   }

}