Interview Q&A / Data Structures & Algorithms

1. How do you implement binary search, and what are the common bugs?

   On a sorted array, keep two pointers low and high, check the middle element, and throw away the half that cannot contain the target. Repeat until found or low passes high. It runs in O(log n). The classic bugs are computing mid as (low + high) / 2, which can overflow in Java or C++, and off-by-one errors in the loop condition and pointer updates.

   BeginnerIn-depthCoding4 min read