midSearching
Find the single element in a sorted array (all others appear twice)
Updated Apr 28, 2026
Short answer
Binary search based on index parity.
Deep explanation
Intermediate searching challenges involve non-standard data structures or specific constraints. Binary search based on index parity.
Real-world example
Finding a word in a partially organized document.
Common mistakes
- Using O(n) for a 2D matrix search when O(log(m*n)) is possible.
Follow-up questions
- Why is mid = (low + high) // 2 potentially dangerous?