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Red-Black Tree Quiz

Questions and Solutions​

1. What is a Red-Black Tree?​

  • Options:
    • A) A binary search tree with additional color properties.
    • B) A tree that only allows red nodes.
    • C) A tree where all nodes are black.
    • D) A tree with no duplicate values.
  • Answer: A) A binary search tree with additional color properties.
  • Explanation: A Red-Black Tree is a binary search tree that follows specific properties to maintain balance, ensuring efficient operations.

2. What are the two colors used in a Red-Black Tree?​

  • Options:
    • A) Red and Blue
    • B) Black and White
    • C) Red and Black
    • D) Green and Yellow
  • Answer: C) Red and Black
  • Explanation: Red-Black Trees use two colors (red and black) to maintain balance and ensure that the tree remains approximately balanced.

3. What is the maximum height of a Red-Black Tree with n nodes?​

  • Options:
    • A) O(n)
    • B) O(log n)
    • C) O(2 log n)
    • D) O(sqrt(n))
  • Answer: B) O(log n)
  • Explanation: The maximum height of a Red-Black Tree is O(log n), ensuring that operations like insertion, deletion, and search remain efficient.

4. Which of the following properties must be true for a Red-Black Tree?​

  • Options:
    • A) The root must be red.
    • B) Red nodes cannot have red children.
    • C) All leaves are red.
    • D) Every path from a node to its leaves must have the same number of red nodes.
  • Answer: B) Red nodes cannot have red children.
  • Explanation: One of the fundamental properties of Red-Black Trees is that red nodes cannot have red children, which helps maintain balance.

5. What is the role of rotations in Red-Black Trees?​

  • Options:
    • A) To delete nodes.
    • B) To maintain the balance of the tree.
    • C) To insert nodes.
    • D) To traverse the tree.
  • Answer: B) To maintain the balance of the tree.
  • Explanation: Rotations are used to restore balance in the tree after insertions and deletions, ensuring the Red-Black properties are maintained.

6. When a new node is inserted into a Red-Black Tree, what color is it initially?​

  • Options:
    • A) Red
    • B) Black
    • C) Blue
    • D) Green
  • Answer: A) Red
  • Explanation: Newly inserted nodes in a Red-Black Tree are always colored red to maintain the tree's balance.

7. In a Red-Black Tree, how do you ensure that the tree remains balanced after an insertion?​

  • Options:
    • A) By performing rotations and recoloring nodes.
    • B) By deleting the inserted node.
    • C) By adjusting the tree's height.
    • D) By increasing the tree's depth.
  • Answer: A) By performing rotations and recoloring nodes.
  • Explanation: Balancing is achieved through rotations and recoloring, following specific rules based on the colors of the affected nodes.

8. Which of the following scenarios requires a right rotation in a Red-Black Tree?​

  • Options:
    • A) Inserting a red node in the left subtree of a left child.
    • B) Inserting a red node in the right subtree of a right child.
    • C) Inserting a red node in the right subtree of a left child.
    • D) Inserting a black node.
  • Answer: A) Inserting a red node in the left subtree of a left child.
  • Explanation: This scenario causes an imbalance that is corrected with a right rotation.

9. What happens if a Red-Black Tree property is violated during an insertion?​

  • Options:
    • A) The tree is deleted.
    • B) The tree is rebalanced.
    • C) The insertion is aborted.
    • D) No action is taken.
  • Answer: B) The tree is rebalanced.
  • Explanation: If any property is violated, the tree undergoes rebalancing through rotations and recoloring to restore its properties.

10. What is the primary advantage of using a Red-Black Tree over a regular Binary Search Tree?​

  • Options:
    • A) It requires less memory.
    • B) It guarantees O(log n) time complexity for insertions, deletions, and searches.
    • C) It can store duplicate values.
    • D) It allows for faster traversals.
  • Answer: B) It guarantees O(log n) time complexity for insertions, deletions, and searches.
  • Explanation: The balanced nature of Red-Black Trees ensures that operations maintain logarithmic time complexity, making them efficient for dynamic sets.