Tree: Depth-First Search - Path Sum
You need to determine if a binary tree has a root-to-leaf path where the sum of node values equals a target sum. Which algorithmic pattern best fits this problem?
You need to determine if a binary tree has a root-to-leaf path where the sum of node values equals a target sum. Which algorithmic pattern best fits this problem?
easy🔍 Pattern Recognition Q1 of Q15
Step-by-Step Solution
Solution:
Step 1: Identify problem requirements
The problem requires checking root-to-leaf paths and summing node values along each path.Step 2: Match pattern to algorithm
Depth-first search (DFS) naturally explores root-to-leaf paths and can accumulate sums during traversal, making it the ideal pattern.Final Answer:
Option D -> Option DQuick Check:
DFS fits path accumulation problems [OK]
Quick Trick: Root-to-leaf sum problems -> DFS pattern [OK]
Common Mistakes:
MISTAKES- Confusing BFS as better for path sums
- Thinking DP is needed for simple path existence
Trap Explanation:
PITFALL- Candidates often pick BFS or DP because they know those patterns but miss that DFS is simpler and direct here.
Interviewer Note:
CONTEXT- Tests candidate's ability to recognize tree traversal patterns for path sums.
Master "Path Sum" in Tree: Depth-First Search
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