Code Snippets

Postorder Traversal in Binary Search Tree

                                    
            
    #include <stdio.h>
    #include <malloc.h>
    
    struct node
    {
        int data;
        struct node *left;
        struct node *right;
    };
    
    struct node *createNode(int data)
    {
        struct node *n;                                 // creating a node pointer
        n = (struct node *)malloc(sizeof(struct node)); // Allocating memory in the heap
        n->data = data;                                 // Setting the data
        n->left = NULL;                                 // Setting the left and right children to NULL
        n->right = NULL;                                // Setting the left and right children to NULL
        return n;                                       // Finally returning the created node
    }
    
    void postOrder(struct node *root)
    {
        if (root != NULL)
        {
            postOrder(root->left);
            postOrder(root->right);
            printf("%d ", root->data);
        }
    }
    
    int main()
    {
        // Constructing the root node - Using Function (Recommended)
        struct node *p = createNode(4);
        struct node *p1 = createNode(1);
        struct node *p2 = createNode(6);
        struct node *p3 = createNode(5);
        struct node *p4 = createNode(2);
    
        // Finally The tree looks like this:
        //      4
        //     / \
        //    1   6
        //   / \
        //  5   2
    
        // Linking the root node with left and right children
        p->left = p1;
        p->right = p2;
        p1->left = p3;
        p1->right = p4;
    
        printf("Postorder Traversal in Binary Search Tree\n");
        postOrder(p);
    
        return 0;
    }