Bird
Raised Fist0

What is the space complexity of the optimal greedy postorder traversal solution for the Binary Tree Cameras problem on a binary tree with height h?

medium🪤 Complexity Trap Q6 of Q15
Tree: Depth-First Search - Binary Tree Cameras
What is the space complexity of the optimal greedy postorder traversal solution for the Binary Tree Cameras problem on a binary tree with height h?
AO(n) due to storing coverage states for all nodes in a separate array
BO(h) due to recursion call stack depth in DFS traversal
CO(1) constant space since no extra data structures are used
DO(n) due to memoization of all subproblems
Step-by-Step Solution
Solution:

  1. Step 1: Identify auxiliary space usage

    The algorithm uses no extra arrays or memo tables; only recursion stack.

  2. Step 2: Recursion stack depth equals tree height h

    Space used is O(h) for call stack, no additional storage.

  3. Step 3: Constant extra variables used

    Only a few variables for counters and states.

  4. Final Answer:

    Option C -> Option C

  5. Quick Check:

    Space dominated by recursion stack depth O(h) [OK]
Quick Trick: Recursion stack depth = O(h) space [OK]
Common Mistakes:
MISTAKES
  • Assuming O(n) space due to arrays or memoization
Trap Explanation:
PITFALL
  • Candidates forget recursion stack counts as space, or confuse with DP table space.
Interviewer Note:
CONTEXT
  • Tests understanding of recursion stack space vs auxiliary data structures
Master "Binary Tree Cameras" in Tree: Depth-First Search

3 interactive learning modes - each teaches the same concept differently

Try ItSolutionTrace

Want More Practice?

15+ quiz questions · All difficulty levels · Free

Free Signup - Practice All Questions
More Tree: Depth-First Search Quizzes
Balanced Binary Tree - Balanced Binary Tree - Quiz 10hard Binary Tree Maximum Path Sum - Binary Tree Maximum Path Sum - Quiz 9hard Binary Tree Preorder Traversal - Binary Tree Preorder Traversal - Quiz 9hard House Robber III (On Tree) - House Robber III (On Tree) - Quiz 8hard House Robber III (On Tree) - House Robber III (On Tree) - Quiz 14medium Lowest Common Ancestor of Binary Tree - Lowest Common Ancestor of Binary Tree - Quiz 8hard Path Sum II (All Root-to-Leaf Paths) - Path Sum II (All Root-to-Leaf Paths) - Quiz 10hard Path Sum II (All Root-to-Leaf Paths) - Path Sum II (All Root-to-Leaf Paths) - Quiz 15hard Path Sum II (All Root-to-Leaf Paths) - Path Sum II (All Root-to-Leaf Paths) - Quiz 14medium Sum Root to Leaf Numbers - Sum Root to Leaf Numbers - Quiz 14medium