AQA 7517 4.3.2.1: Simple tree-traversal algorithms
The free BugBot lesson that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
Breadth-first and depth-first traversal visit every vertex of a graph. A binary tree has three standard depth-first orders of its own, and each has its uses: printing a binary search tree in order, copying a tree, turning an expression into Reverse Polish notation. The three differ in only one thing: when each node is visited.
- Three orders
- The outline method
- What each traversal is for
- Expression trees
- Breadth-first on a tree
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- A4.7 Tree traversals Trees and graphs
Pre-order, in-order and post-order, the outline method, expression trees and what each traversal is for.
Try it on a robot
The task from A4.7 Tree traversals, running here. Change the program and press Run.
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