Solving Serialize and Deserialize using BFS/DFS.

Problem

Convert tree to string and back.

Pattern

This problem demonstrates the BFS/DFS pattern.

Approach

Preorder with null markers.

Solution 

  // Solution for Serialize and Deserialize
// Pattern: BFS/DFS
// O(n) time

Complexity

O(n) time

Best Practices

  • Identify the pattern before coding — pattern recognition saves time
  • Handle edge cases: empty input, single element, duplicates
  • Use descriptive variable names even in timed interviews
  • Test with the provided examples plus one custom case