NIST

postorder traversal

(algorithm)

Definition: Process all nodes of a tree by recursively processing all subtrees, then finally processing the root.

Also known as postfix traversal.

Generalization (I am a kind of ...)
tree traversal, depth-first search.

See also in-order traversal, preorder traversal, level-order traversal, Cupif-Giannini tree traversal.

Note: For instance, if the "processing" is just printing, a tree is printed as "(first subtree) (second subtree) ... (last subtree) root". Here is pseudocode for a binary tree:

 postorder(tree)
begin
if tree is null, return;

postorder(tree.left_subtree);
postorder(tree.right_subtree);
print(tree.root);
end

Author: PEB

More information

animation (Java)


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If you have suggestions, corrections, or comments, please get in touch with Paul Black.

Entry modified 24 August 2017.
HTML page formatted Fri Feb 23 10:06:08 2018.

Cite this as:
Paul E. Black, "postorder traversal", in Dictionary of Algorithms and Data Structures [online], Vreda Pieterse and Paul E. Black, eds. 24 August 2017. (accessed TODAY) Available from: https://www.nist.gov/dads/HTML/postorderTraversal.html