Question

How to insert numbers in a binary search tree?

Answer 1

// C program to demonstrate insert operation in binary search tree

#include<stdio.h>

#include<stdlib.h>

  

struct node

{

    int key;

    struct node *left, *right;

};

  

// A utility function to create a new BST node

struct node *newNode(int item)

{

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

    temp->key = item;

    temp->left = temp->right = NULL;

    return temp;

}

  

// A utility function to do inorder traversal of BST

void inorder(struct node *root)

{

    if (root != NULL)

    {

        inorder(root->left);

        printf("%d \n", root->key);

        inorder(root->right);

    }

}

  

/* A utility function to insert a new node with given key in BST */

struct node* insert(struct node* node, int key)

{

    /* If the tree is empty, return a new node */

    if (node == NULL) return newNode(key);

 

    /* Otherwise, recur down the tree */

    if (key < node->key)

        node->left  = insert(node->left, key);

    else if (key > node->key)

        node->right = insert(node->right, key);  

 

    /* return the (unchanged) node pointer */

    return node;

}

  

// Driver Program to test above functions

int main()

{

    /* Let us create following BST

              50

           /     \

          30      70

         /  \    /  \

       20   40  60   80 */

    struct node *root = NULL;

    root = insert(root, 50);

    insert(root, 30);

    insert(root, 20);

    insert(root, 40);

    insert(root, 70);

    insert(root, 60);

    insert(root, 80);

  

    // print inoder traversal of the BST

    inorder(root);

  

    return 0;

}