Recall & Review
beginner
What is the Boundary Traversal of a binary tree?
Boundary Traversal is a way to visit all the nodes on the boundary of a binary tree. It includes the left boundary (top to bottom), all leaf nodes (left to right), and the right boundary (bottom to top).
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beginner
Which nodes are included in the left boundary during boundary traversal?
The left boundary includes all nodes on the path from the root to the left-most leaf, excluding leaf nodes if they are already counted in the leaf nodes section.
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beginner
How do you identify leaf nodes in a binary tree?
Leaf nodes are nodes that do not have any children (no left or right child). They are the bottom-most nodes in the tree.
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intermediate
What is the order of nodes visited in boundary traversal?
The order is: root node, left boundary (top to bottom), leaf nodes (left to right), and right boundary (bottom to top).
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intermediate
Why do we traverse the right boundary from bottom to top in boundary traversal?
We traverse the right boundary from bottom to top to maintain the anti-clockwise order of the boundary traversal, ensuring nodes are visited in the correct sequence.
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Which nodes are NOT included in the left boundary during boundary traversal?
✗ Incorrect
Leaf nodes are counted separately in the leaf nodes section, so they are excluded from the left boundary to avoid duplication.
In boundary traversal, how are leaf nodes visited?
✗ Incorrect
Leaf nodes are visited from left to right to cover all leaves in the tree in order.
What is the first node visited in boundary traversal?
✗ Incorrect
The traversal always starts with the root node.
How is the right boundary traversed in boundary traversal?
✗ Incorrect
The right boundary is traversed from bottom to top to maintain the anti-clockwise order.
Which of these nodes is NOT part of the boundary traversal?
✗ Incorrect
Only nodes on the boundary (left boundary, leaves, right boundary, and root) are included, internal nodes inside the tree are not.
Explain the steps to perform boundary traversal of a binary tree.
Think about visiting edges and leaves in an anti-clockwise direction.
You got /4 concepts.
Describe how to avoid counting leaf nodes twice in boundary traversal.
Leaves appear in both boundary and leaf sections, so handle carefully.
You got /4 concepts.