Program to Determine Whether all Leaves are at Same Level

Q. Program to determine whether all leaves are at same level.

Explanation

In this program, we need to check whether all the leaves of the given binary tree are at same level or not.

A Node is said to be leaf if it doesn’t have any child node. In the below diagram, nodes 4, 5 and 6 are leaf nodes as they don’t have any child node. Nodes 4, 5 and 6 are present at the same level, i.e., Level 2.

Program to determine whether all leaves are at same level

Algorithm

Define Node class which has three attributes namely: data left and right. Here, left represents the left child of the node and right represents the right child of the node.
When a node is created, data will pass to data attribute of the node and both left and right will be set to null.
Define another class which has two attribute root and level.
1. Root represents the root node of the tree and initializes it to null.
2. The level will be used to store the level of the first encountered leaf node.
isSameLevel() will check whether all leaves of given binary tree are at same level or not:
1. It checks whether the root is null, which means the tree is empty.
2. If the tree is not empty, traverse through the tree and check for leaf node whose left and right children are null.
3. CurrentLevel will keep track of current level being traversed.
4. When the first leaf node is encountered, store the value of currentLevel in variable level.
5. Traverse recursively through all level, check for subsequent leaf nodes. If currentLevel of all leaf is equal to the value stored in level then, all leaves are at same level.

Solution

Python

  #Represent a node of binary tree  class Node:      def __init__(self,data):          #Assign data to the new node, set left and right children to None          self.data = data;          self.left = None;          self.right = None;     class LeafLevel:      def __init__(self):          #Represent the root of binary tree          self.root = None;          #It will store level of first encountered leaf           self.level = 0;                #isSameLevel() will check whether all leaves of the binary tree is at same level or not      def isSameLevel(self, temp, currentLevel):                    #Check whether tree is empty          if(self.root == None):              print(“Tree is empty”);              return true;                        else:              #Checks whether node is None              if(temp == None):                  return True;                                if(temp.left == None and temp.right == None):                  #If first leaf is encountered, set level to current level                  if(self.level == 0):                      self.level = currentLevel;                      return True;                                        #Checks whether the other leaves are at the same level as that of the first leaf                  else:                      return (self.level == currentLevel);                                    #Checks for leaf node in left and right subtree recursively.              return  (self.isSameLevel(temp.left, currentLevel + 1) and self.isSameLevel(temp.right, currentLevel + 1));                    bt = LeafLevel();  #Add nodes to the binary tree  bt.root = Node(1);  bt.root.left = Node(2);  bt.root.right = Node(3);  bt.root.left.left = Node(4);  bt.root.right.left = Node(5);  bt.root.right.right = Node(6);     #Checks whether all leaves of given binary tree is at same level  if(bt.isSameLevel(bt.root, 1)):      print(“All leaves are at same level”);  else:      print(“All leaves are not at same level”);  

Output:

All leaves are at same level

C

  #include <stdio.h>  #include <stdlib.h>  #include <stdbool.h>     //Represent a node of binary tree  struct node{      int data;      struct node *left;      struct node *right;  };     //Represent the root of binary tree  struct node *root = NULL;     //It will store level of first encountered leaf   static int level = 0;        //createNode() will create a new node  struct node* createNode(int data){      //Create a new node      struct node *newNode = (struct node*)malloc(sizeof(struct node));      //Assign data to newNode, set left and right children to NULL      newNode->data= data;      newNode->left = NULL;      newNode->right = NULL;            return newNode;  }     //isSameLevel() will check whether all leaves of the binary tree is at the same level or not  bool isSameLevel(struct node *temp, int currentLevel ) {            //Check whether tree is empty      if(root == NULL){          printf(“Tree is emptyn”);          return true;      }      else {          //Checks whether node is null          if(temp == NULL)              return true;             if(temp->left == NULL && temp->right == NULL) {              //If first leaf is encountered, set level to current level              if(level == 0) {                  level = currentLevel ;                  return true;              }              //Checks whether the other leaves are at the same level of that of first leaf              else                  return (level == currentLevel) ;           }                    //Checks for leaf node in left and right subtree recursively.          return  (isSameLevel(temp->left, currentLevel + 1) && isSameLevel(temp->right, currentLevel + 1)) ;       }  }     int main()  {      //Add nodes to the binary tree      root = createNode(1);      root->left = createNode(2);      root->right = createNode(3);      root->left->left = createNode(4);      root->right->left = createNode(5);      root->right->right = createNode(6);            //Checks whether all leaves of given binary tree is at same level      if(isSameLevel(root, 1))           printf(“All leaves are at same level”);      else          printf(“All leaves are not at same level”);         return 0;  }  

Output:

All leaves are at same level

JAVA

  public class LeafLevel {            //Represent a node of binary tree      public static class Node{          int data;          Node left;          Node right;                    public Node(int data){              //Assign data to the new node, set left and right children to null              this.data = data;              this.left = null;              this.right = null;              }          }            //Represent the root of binary tree      public Node root;            //It will store level of first encountered leaf       public static int level = 0;          public LeafLevel(){          root = null;      }          //isSameLevel() will check whether all leaves of the binary tree is at same level or not      public boolean isSameLevel(Node temp, int currentLevel ) {                    //Check whether tree is empty          if(root == null){            System.out.println(“Tree is empty”);            return true;          }          else {              //Checks whether node is null              if(temp==null)                  return true;                 if(temp.left == null && temp.right == null) {                  //If first leaf is encountered, set level to current level                  if(level == 0) {                      level = currentLevel ;                      return true;                  }                  //Checks whether the other leaves are at same level of that of first leaf                  else                      return (level == currentLevel) ;               }                            //Checks for leaf node in left and right subtree recursively.              return  (isSameLevel(temp.left, currentLevel + 1) && isSameLevel(temp.right, currentLevel + 1)) ;           }      }          public static void main (String[] args) {                    LeafLevel bt = new LeafLevel();          //Add nodes to the binary tree          bt.root = new Node(1);          bt.root.left = new Node(2);          bt.root.right = new Node(3);          bt.root.left.left = new Node(4);          bt.root.right.left = new Node(5);          bt.root.right.right = new Node(6);                //Checks whether all leaves of given binary tree is at same level          if(bt.isSameLevel(bt.root, 1))               System.out.println(“All leaves are at same level”);          else              System.out.println(“All leaves are not at same level”);    }  }  

Output:

All leaves are at same level

C#

  using System;  namespace Tree   {                           public class Program      {          //Represent a node of binary tree          public class Node<T>{              public T data;              public Node<T> left;              public Node<T> right;                            public Node(T data) {                  //Assign data to the new node, set left and right children to null                  this.data = data;                  this.left = null;                  this.right = null;              }          }                    public class LeafLevel<T>{              //Represent the root of binary tree              public Node<T> root;                            //It will store level of first encountered leaf               public static int level = 0;                            public LeafLevel(){                  root = null;              }                        //isSameLevel() will check whether all leaves of the binary tree is at same level or not              public Boolean isSameLevel(Node<int> temp, int currentLevel ) {                     //Check whether tree is empty                  if(root == null){                    Console.WriteLine(“Tree is empty”);                    return true;                  }                  else {                      //Checks whether node is null                      if(temp==null)                          return true;                         if(temp.left == null && temp.right == null) {                          //If first leaf is encountered, set level to current level                          if(level == 0) {                              level = currentLevel ;                              return true;                          }                          //Checks whether the other leaves are at same level of that of first leaf                          else                              return (level == currentLevel) ;                       }                         //Checks for leaf node in left and right subtree recursively.                      return  (isSameLevel(temp.left, currentLevel + 1) && isSameLevel(temp.right, currentLevel + 1)) ;                   }              }          }                    public static void Main()          {              LeafLevel<int> bt = new LeafLevel<int>();              //Add nodes to the binary tree              bt.root = new Node<int>(1);              bt.root.left = new Node<int>(2);              bt.root.right = new Node<int>(3);              bt.root.left.left = new Node<int>(4);              bt.root.right.left = new Node<int>(5);              bt.root.right.right = new Node<int>(6);                 //Checks whether all leaves of given binary tree is at same level              if(bt.isSameLevel(bt.root, 1))                   Console.WriteLine(“All leaves are at same level”);              else                  Console.WriteLine(“All leaves are not at same level”);                              }          }  }  

Output:

All leaves are at same level

PHP

  <!DOCTYPE html>  <html>  <body>  <?php  //Represent a node of binary tree  class Node{      public $data;      public $left;      public $right;            function __construct($data){          //Assign data to the new node, set left and right children to NULL          $this->data = $data;          $this->left = NULL;          $this->right = NULL;      }  }  class LeafLevel{      //Represent the root of binary tree      public $root;      //It will store level of first encountered leaf       public $level = 0;            function __construct(){          $this->root = NULL;          $this->level = 0;      }            //isSameLevel() will check whether all leaves of the binary tree is at same level or not      function isSameLevel($temp, $currentLevel ) {                    //Check whether tree is empty          if($this->root == NULL){              print(“Tree is empty <br>”);                return true;          }          else {              //Checks whether node is null              if($temp == NULL)                  return true;                 if($temp->left == NULL && $temp->right == NULL) {                  //If first leaf is encountered, set level to current level                  if($this->level == 0) {                      $this->level = $currentLevel ;                      return true;                  }                  //Checks whether the other leaves are at same level of that of first leaf                  else                      return ($this->level == $currentLevel) ;               }                            //Checks for leaf node in left and right subtree recursively.              return  ($this->isSameLevel($temp->left, $currentLevel + 1) && $this->isSameLevel($temp->right, $currentLevel + 1)) ;           }      }  }  $bt = new LeafLevel();  //Add nodes to the binary tree  $bt->root= new Node(1);  $bt->root->left = new Node(2);  $bt->root->right = new Node(3);  $bt->root->left->left = new Node(4);  $bt->root->right->left = new Node(5);  $bt->root->right->right = new Node(6);     //Checks whether all leaves of given binary tree is at same level  if($bt->isSameLevel($bt->root, 1))       print(“All leaves are at same level”);  else      print(“All leaves are not at same level”);    ?>  </body>  </html>  

Output:

All leaves are at same level

Next TopicPrograms List

Q. Program to determine whether all leaves are at same level.

Explanation

Algorithm

Solution

Python

C

JAVA

C#

PHP

Potential Energy

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