Trees
Level-Order Traversal
Visit a tree breadth-first with a queue.
Algorithm
The canonical tree is 4(2(1,3),6(5,7)), so this SQL DSA
implementation can be compared directly with the rest of the DSA track.
Basic Implementation
basic.sql
SELECT '[4, 2, 6, 1, 3, 5, 7]';
Complexity
- Time: O(n)
- Space: O(w) queue space
Implementation notes
- Render tree structure explicitly instead of printing node objects.
- The replay highlights the node, traversal state, queue, path, or search cursor that changes at each step.
level order
Level-order traversal uses a queue to visit shallower nodes first.