What traversal method visits a node after its children?

The traversal method that visits a node after its children is postorder traversal. In postorder traversal, the algorithm follows a specific sequence: it first processes all the left subtree nodes, then it processes all the right subtree nodes, and finally, it visits the node itself. This is akin to completing the exploration of both children before acknowledging the parent node.

This approach is particularly useful in scenarios where a computation needs to be completed for all child nodes before the parent node is processed, such as in calculating the size of a subtree or evaluating expressions in a syntax tree. By ensuring that a node is not visited until both of its children have been explored, postorder traversal guarantees that any necessary operations on the child nodes are completed before dealing with the parent.

For context, other traversal methods, like inorder and preorder, follow different sequences that do not adhere to visiting the node after its children. Inorder traversal generally processes the left child, then the node itself, and finally the right child, while preorder visits the node first before its children.