Pre-Order Tree Traversal Algorithm

1

Three Types of Depth-First Search

Alyce Brady CS 470 Data Structures CS 510
Computer Algorithms
2

Depth-First Search
Pre-order Traversal Root - Left Child - Right
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Pre-order TraversalRoot - Left Child - Right
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Pre-order TraversalRoot - Left Child - Right
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Pre-order TraversalRoot - Left Child - Right
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Pre-order TraversalRoot - Left Child - Right
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Pre-order TraversalRoot - Left Child - Right
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Pre-order TraversalRoot - Left Child - Right
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A B D
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Pre-order TraversalRoot - Left Child - Right
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A B D
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Pre-order TraversalRoot - Left Child - Right
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A B D H
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Pre-order TraversalRoot - Left Child - Right
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A B D H
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Pre-order TraversalRoot - Left Child - Right
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Pre-order TraversalRoot - Left Child - Right
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A B D H I
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Pre-order TraversalRoot - Left Child - Right
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A B D H I
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Pre-order TraversalRoot - Left Child - Right
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A B D H I
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Pre-order TraversalRoot - Left Child - Right
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A B D H I
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M G
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Pre-order TraversalRoot - Left Child - Right
Child
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A B D H I E J K C F L M G
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Pre-order TraversalRoot - Left Child - Right
Child
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A B D H I E J K C F L M G N
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Pre-order TraversalRoot - Left Child - Right
Child
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A B D H I E J K C F L M G N
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M G N
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M G N O
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M G N O
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M G N O
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M G N O
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Pre-order TraversalRoot - Left Child - Right
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A B D H I E J K C F L M G N O
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Pseudo-Code forPre-order Traversal

• pre-traverse
• visit current node e.g., print value
• pre-traverse left subtree
• pre-traverse right subtree