Go4Expert - Binary search tree traversal-Inorder,preorder,postorder.

/*This program takes the elements from the user in random order & then arranges it in
form of Binary Search Tree.It then asks user for traversal*/
Code:


#include<stdio.h>                          // including headerfiles

#include<conio.h>

#include<stdlib.h>

struct tree                                        //creating structure

{ 

int data;                         //data field of node

struct tree *lchild,*rchild;               //left child & right child of node

};

struct tree *insert(struct tree *p,int n);     //function for insertion

void inorder(struct tree *p);                      //function for inorder traversal

void preorder(struct tree *p);                   // function for preorder traversal

void postorder(struct tree *p);                  // function for postorder traversal

void main()                      //main function

{ 

int x,y,i;                                    

struct tree *root;

clrscr();

root=NULL;

printf("Enter the no. of nodes in the tree\n");

scanf("%d",&x);

while(x-->0)

{

printf("Enter the data part of the node\n");

scanf("%d",&y);

root=traverse(root,y);

}

clrscr();

printf("\t\tEnter the traversal u want\n");

printf("1.Inorder.\n2.Preorder.\n3.Postorder.\n");

scanf("%d",&i);

switch(i)

{

case 1:

{

printf("The inorder traversal is \n");

inorder(root);                        //function calling

}

break;

case 2:

{

printf("The preorder traversal is\n");

preorder(root);                           //function calling

}

break;

case 3:

{

printf("The postorder traversal is\n");

postorder(root);                            // function calling

}

break;

}

getch();

}



//function definition for insertion

struct tree *traverse(struct tree *p,int n)               

{

static struct tree *temp1,*temp2;

if(p==NULL)

{

p=(struct tree *)malloc(sizeof(struct tree));

p->data=n;

p->lchild=p->rchild=NULL;

}

else

{

temp1=p;

while(temp1!=NULL)

{

temp2=temp1;

if(n<temp1->data)

temp1=temp1->lchild;

else

temp1=temp1->rchild;

}

if(temp2->data>n)

{

temp2->lchild=(struct tree *)malloc(sizeof(struct tree));

temp2=temp2->lchild;

temp2->data=n;

temp2->lchild=temp2->rchild=NULL;

}

else

{

temp2->rchild=(struct tree *)malloc(sizeof(struct tree));

temp2=temp2->rchild;

temp2->data=n;

temp2->lchild=temp2->rchild=NULL;

}

}

return p;

}

//function definition for inorder traversal



void inorder(struct tree *p)

{

if(p!=NULL)

{

inorder(p->lchild);

printf("%d ",p->data);

inorder(p->rchild);

}

}



//function definition for preorder traversal

void preorder(struct tree *p)

{

if(p!=NULL)

{

printf("%d ",p->data);

preorder(p->lchild);

preorder(p->rchild);

}

}



//function definition for postorder traversal

void postorder(struct tree *p)

{

if(p!=NULL)

{

postorder(p->lchild);

postorder(p->rchild);

printf("%d ",p->data);

}

}