Trees· 10 min

Pre-order Traversal

Root → Left → Right — useful for copying

Setup

Step 1 / 30

Current step

1 / 30

Start at the root — call preorder(50)

Step log

7 nodes · depth 3 · drag to pan, scroll to zoom
Current / on path
Visited
Just inserted
Found
preorder_traversal.java
1void preorder(Node node) {
2    if (node == null) return;
3    visit(node);
4    preorder(node.left);
5    preorder(node.right);
6}
● Java
Call stack1 frame
preorder(50)active
Traversal output0 / 7

nothing visited yet

Pre-order Traversal

Pre-order traversal visits every node in a specific order. Pre-order visits the root before its subtrees — useful for copying a tree.

Nodes
7
Mode
traversal
Time (avg)
O(log n)
Time (worst)
O(n)
50307020406080
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