Insertion in a Binary Tree (Level Order) in C

March 4, 2023

Insertion in a binary tree

 

Given a tree and a key, add a node in the first available node in the tree. After adding the node, print the level order traversal. In this article, Queue data structure is used to add a node.

Insertion in tree in C

Insertion in a Binary Tree In C

Algorithm :

  • Create a queue q.
  • If root is NULL, add node and return.
  • Else continue until q is not empty.
  • If a child does not exists, add the node there.
  • Otherwise add the node to the leftmost node.
insertion in binary tree
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AVL Trees

AVL Tree Insertion

AVL Tree Deletion

Find size of the Binary tree

Find height of the Binary Tree

C code for insertion a node in binary tree

Run 
#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;
  struct Node *right;
};
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);
};

void printCurrentLevel (struct Node *root, int level);
int height (struct Node *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);
    }
}

void printLevelOrder (struct Node *root)
{
  int h = height (root);
  int i;
  for (i = 1; i <= h; i++)
    printCurrentLevel (root, i);
}				/* Print nodes at a current level */

void printCurrentLevel (struct Node *root, int level)
{
  if (root == NULL)
    return;
  if (level == 1)
    printf ("%d ", root->data);
  else if (level > 1)
    {
      printCurrentLevel (root->left, level - 1);
      printCurrentLevel (root->right, level - 1);
    }
}

struct Node *insert (struct Node *root, int val)
{

  if (root == NULL)
    return newNode (val);

  if (root->data < val)
    root->right = insert (root->right, val);

  else if (root->data > val)
    root->left = insert (root->left, val);

  return root;
}

// Driver code
int main ()
{
  struct Node *root = newNode (10);
  root->left = newNode (11);
  root->left->left = newNode (7);
  root->right = newNode (9);
  root->right->left = newNode (15);
  root->right->right = newNode (8);

  printf ("Level order traversal before insertion: ");
  printLevelOrder (root);
  printf ("\n");

  int key = 12;
  root = insert (root, key);

  printf ("Level order traversal after insertion: ");
  printLevelOrder (root);
  printf ("\n");

  return 0;
}

Output :


Level order traversal before insertion : 10 11 9 7 15 8

Level order traversal after insertion : 10 11 9 7 15 8 12

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Introduction to Trees

Binary Trees

Binary Search Trees

Traversals

  • Traversal in Trees
  • Tree Traversals: Breadth-First Search (BFS) : C | C++ | Java
  • Tree Traversals: Depth First Search (DFS) : C | C++ | Java
  • Construct a Binary Tree from Postorder and Inorder

B – Trees

AVL Trees

  • AVL Trees
    • AVL Trees: Introduction
    • AVL Tree Insertion : C | C++ | Java
    • AVL Tree Deletion : C | C++ | Java
    • Insertion in a Binary Tree (Level Order) – C | C++ | Java
    • Searching in Binary Tree – C | C++ | Java
    • Searching in a Binary Search Tree – C | C++ | Java

Complete Programs for Trees

  • Depth First Traversals – C | C++ | Java
  • Level Order Traversal – C | C++ | Java
  • Construct Tree from given Inorder and Preorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Inorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Preorder traversal – C | C++ | Java
  • Find size of the Binary tree – C | C++ | Java
  • Find the height of binary tree – C | C++ | Java
  • Find maximum in binary tree – C | C++ | Java
  • Check whether two tree are identical- C| C++| Java
  • Spiral Order traversal of Tree- C | C++| Java
  • Level Order Traversal Line by Line – C | C++| Java
  • Hand shaking lemma and some Impotant Tree Properties.
  • Check If binary tree if Foldable or not.- C| C++| Java
  • check whether tree is Symmetric – C| C++| Java.
  • Check for Children-Sum in Binary Tree- C|C++| Java
  • Sum of all nodes in Binary Tree- C | C++ | Java
  • Lowest Common Ancestor in Binary Tree- C | C++ | Java

Introduction to Trees

Binary Trees

Binary Search Trees

Traversals

  • Traversal in Trees
  • Tree Traversals: Breadth-First Search (BFS) : C | C++ | Java
  • Tree Traversals: Depth First Search (DFS) : C | C++ | Java
  • Construct a Binary Tree from Postorder and Inorder

B – Trees

AVL Trees

  • AVL Trees
    • AVL Trees: Introduction
    • AVL Tree Insertion :  C | C++ | Java
    • AVL Tree Deletion : C | C++ | Java
    • Insertion in a Binary Tree (Level Order) – C | C++ | Java
    • Searching in Binary Tree – C | C++ | Java
    • Searching in a Binary Search Tree – C | C++ | Java

Complete Programs for Trees

  • Depth First Traversals – C | C++ | Java
  • Level Order Traversal – C | C++ | Java
  • Construct Tree from given Inorder and Preorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Inorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Preorder traversal – C | C++ | Java
  • Find size of the Binary tree – C | C++ | Java
  • Find the height of binary tree – C | C++ | Java
  • Find maximum in binary tree – C | C++ | Java
  • Check whether two tree are identical- C| C++| Java
  • Spiral Order traversal of Tree- C | C++| Java
  • Level Order Traversal LIne by Line – C | C++| Java
  • Hand shaking lemma and some Impotant Tree Properties.
  • Check If binary tree if Foldable or not.- C| C++| Java
  • check whether tree is Symmetric  C| C++| Java.
  • Check for Children-Sum in Binary Tree- C|C++| Java
  • Sum of all nodes in Binary Tree- C | C++ | Java
  • Lowest Common Ancestor in Binary Tree. C | C++ | Java