level_order_tree_traversal_spiralorder

// Recursive C program for level order traversal of Binary Tree
#include <stdio.h>
#include <stdlib.h>

/* A binary tree node has data, pointer to left child
   and a pointer to right child */
struct node
{
    int data;
    struct node* left, *right;
};

/* Function protoypes */
void printGivenLevel(struct node* root, int level,int counter);
int height(struct node* node);
struct node* newNode(int data);

/* Function to print level order traversal a tree*/
void printLevelOrder(struct node* root)
{
    int h = height(root);
    int i,j;
    for (i=1; i<=h; i++){
        j=i;
        printGivenLevel(root,i,j);
}
}
/* Print nodes at a given level */
void printGivenLevel(struct node* root, int level ,int counter)
{
    if (root == NULL)
        return;
    if (level == 1)
        printf("%d ", root->data);

    else if (level > 1 && (counter%2)!=0)
    {
        printGivenLevel(root->right, level-1,counter);
        printGivenLevel(root->left, level-1,counter);
    }

    else
    {
        printGivenLevel(root->left, level-1,counter);
        printGivenLevel(root->right, level-1,counter);
    }
}

/* Compute the "height" of a tree -- the number of
    nodes along the longest path from the root node
    down to the farthest leaf node.*/
int height(struct node* node)
{
    if (node==NULL)
        return 0;
    else
    {
        /* compute the height of each subtree */
        int lheight = height(node->left);
        int rheight = height(node->right);

        /* use the larger one */
        if (lheight > rheight)
            return(lheight+1);
        else return(rheight+1);
    }
}

/* Helper function that allocates a new node with the
   given data and NULL left and right pointers. */
struct node* newNode(int data)
{
    struct node* node = (struct node*)
                        malloc(sizeof(struct node));
    node->data = data;
    node->left = NULL;
    node->right = NULL;

    return(node);
}

/* Driver program to test above functions*/
int main()
{
    struct node *root = newNode(1);
    root->left        = newNode(2);
    root->right       = newNode(3);
    root->right->left = newNode(1);
    root->right->right= newNode(9);
    root->left->left  = newNode(4);
    root->left->right = newNode(5);
   root->left->left->left  = newNode(6);
    root->left->right->left = newNode(8);
    root->left->right->left->left= newNode(0);

    root->left->right->left->right= newNode(3);
    root->left->right->left->right->left= newNode(7);
    root->left->right->left->right->right= newNode(5);
    root->left->right->left->right->left->left= newNode(9);
    root->left->right->left->right->left->right= newNode(6);


    printf("Level Order traversal of binary tree is \n");
/*int l;
    l=height(root);
printf("%d",l);
   */
   printLevelOrder(root);
    return 0;
}