Preorder Tree Traversal

Root -> Left -> Right recursion visualizer

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Python Code

10 
●    def recursivePreorder(self, root, arr):
12        # Base case: no node to process
13        if root is None:
14            return
15        arr.append(root.data)
16        self.recursivePreorder(root.left, arr)
17        self.recursivePreorder(root.right, arr)
18
Current Line (11): Function Entry

Tree Structure

1234567
Operation:ENTER:

Traversal Progress

Current Node

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Phase

Enter Function

Result Array

Traversal result appears here...
Step 1: ENTER:

Recursion Stack

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Step Explanation

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Click "Next Step" to begin. We will follow Root -> Left -> Right and explain each highlighted code line.

  • > Start from recursivePreorder(root, arr).
  • > Watch call stack, highlighted line, and result array together.
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