[Tree traversal](https://www.educative.io/answers/what-is-tree-traversal) refers to visiting all the nodes of a tree exactly once. Visiting means doing something to the node. It can be as basic as printing the node. 

**Post-order traversal** is one of the multiple methods to traverse a tree. It is mainly used for tree deletion.

# Basic Algorithm

The following algorithm is specific to a [binary tree](https://www.educative.io/answers/what-is-a-binary-search-tree) but can be generalized​ to an n-ary tree (a tree where each node can have at most​ n children nodes).

1. Recursively traverse the left subtree.
2. Recursively traverse the right subtree.
3. Visit the root.


For an n-ary tree:
1. Traverse the subtrees from left to right.
2. Visit the root node.

# Implementation in C++

The following code snippet implements post-order traversal for a binary tree.

#include <iostream>
using namespace std;

struct Tree
{
	char data;
	Tree *left;
	Tree *right;
  Tree(char data) 
    { 
        this -> data = data; 
        left = NULL;
        right = NULL; 
    }     
};
void PostOrderTraversal(Tree *node)
{
	if(node == NULL){
    return;
  }
  else{
    PostOrderTraversal(node -> left);
    PostOrderTraversal(node -> right);
    cout << node -> data << ", ";
  } 
}
int main() {
  Tree *root = new Tree('a'); 
  root -> left = new Tree('b'); 
  root -> right = new Tree('c'); 
  root -> left -> left = new Tree('d'); 
  root -> left -> left -> left = new Tree('e');
  root -> left -> left -> right = new Tree('f');  
  PostOrderTraversal(root);
  return 0;
}

What is post-order traversal?

Tree traversal refers to visiting all the nodes of a tree exactly once. Visiting means doing something to the node. It can be as basic as printing the node. Post-order traversal is one of the multiple methods to traverse a tree. It is mainly used for tree deletion. Basic Algorithm The following algorithm is specific to a binary tree but can be generalized​ to an n-ary tree (a tree where each node can have at most​ n children nodes).  Recursively traverse the left subtree. Recursively traverse the right subtree. Visit the root.  