PREORDER | TRAVERSAL TECHNIQUE

                 PREORDER  | TRAVERSING TECHNIQUE

A Short Trick

Let we understand the PREORDER TRAVERSING TECHNIQUE from the following binary tree.

Suppose we have any binary tree such as:

80 , 50 , 100 , 45 , 95 , 110 , 47 , 99 , 115 , 97

Now we find  Preorder sequence of following binary tree.

First mark every node at the right side of node like

Now we will start traversing from node 80 like

Now here preorder sequence will be:

PREORDER: 80 , 50 , 45 , 47 , 100 , 95 , 99 , 97 , 110 , 115

RECURSIVE PROCEDURE FOR PREORDER

void Preorder( struct node  *root)

{

    if ( root 1=NULL)

    {

        Printf ( "%d", root➜data);

        Preorder ( root ➜lc);

        Preorder (root➜rc);

    }

}

NON RECURSIVE FUNCTION FOR PREORDER

void Preorder(structnode *root)

{

    structnode *nodestack[50], *temp=root;

    int tos= 0 ;

    node stack[Tos] = NULL;

    temp=root;

    while (temp 1 = NULL)

    {

        printf(" %d ", temp➜data);

        if (temp ➜ rc != NULL)

        {

            node stack[++Tos] = temp ➜ rc;

        }

        if (temp ➜ lc != NULL )

        {

            temp = temp ➜ lc;

        }

        else

        {

            temp = node stack [Tos--];

    }

    

}