Write a progtam to calculate size of a tree

Recursion Steps:

  Size of a tree= 1+size of left subtree + size of right subtree

  Base case : return zero if  a node is null


Code:     Time:O(n)

class Node{
    int data;
    Node left, right;
    Node(int data){
        this.data = data;
    }
}

public class SizeOfBinaryTree {
      static int calculateSize(Node node){
          if(node == null){
              return 0;
          }
         
          return (1+calculateSize(node.left)+calculateSize(node.right));
      }
     
      public static void main(String[] args){
          Node node = new Node(5);
          node.left = new Node(6);
          node.right = new Node(7);
          node.right.right = new Node(8);
         
          System.out.println(calculateSize(node));
      }
}








Output:
 4













































































































































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