Java: Get the Postorder traversal of its nodes' values of a given a binary tree

Java Basic: Exercise-127 with Solution

Write a Java program to get the Postorder traversal of its nodes' values in a binary tree.

Sample Binary Tree

Postorder Traversal:

Sample Solution:

Java Code:

class Node
{
    int key;
    Node left, right;

    public Node(int item)
    {
        key = item;
        left = right = null;
    }
}

class BinaryTree
{
  // Root of Binary Tree
    Node root;

    BinaryTree()
    {
        root = null;
    }

  // Print the nodes of binary tree

    void print_Postorder(Node node)
    {
        if (node == null)
            return;

        print_Postorder(node.left);

        print_Postorder(node.right);

        System.out.print(node.key + " ");
    }

   // Wrappers over above recursive functions
    void print_Postorder()  
	{   
	   print_Postorder(root);  
	}
        public static void main(String[] args)
    {
       BinaryTree tree = new BinaryTree();
        tree.root = new Node(55);
        tree.root.left = new Node(21);
        tree.root.right = new Node(80);
        tree.root.left.left = new Node(9);
        tree.root.left.right = new Node(29);
        tree.root.right.left = new Node(76);
        tree.root.right.right = new Node(91);

        System.out.println("\nPostorder traversal of binary tree is: ");
        tree.print_Postorder();
    }
}

Sample Output:

Postorder traversal of binary tree is: 
9 29 21 76 91 80 55  

Flowchart:

Java Code Editor:

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