Solve Time-Window and Binary Swap Problems
Company: SoFi
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: easy
Interview Round: Technical Screen
This online assessment contained two coding problems:
1. **Maximum requests in a time window**
You are given a non-decreasing integer array `requestTimes`, where `requestTimes[i]` is the second at which the `i`-th request arrives, and an integer `windowSize`. Return the maximum number of requests that occur within any inclusive time interval of length `windowSize` seconds. In other words, find the largest number of elements that can fit inside some interval `[t, t + windowSize]`.
2. **Simultaneous swaps in a binary string**
You are given a binary string `s` consisting only of `'0'` and `'1'`. Every second, all adjacent occurrences of `'01'` are swapped simultaneously to become `'10'`. Repeat this process until the string no longer contains `'01'`. Return the number of seconds required.
Example: `s = "001011"` transforms as follows:
`001011 -> 010101 -> 101010 -> 110100 -> 111000`
So the answer is `4` seconds.
Quick Answer: This assessment evaluates algorithmic proficiency in time-based counting and synchronous string transformation, covering competencies in windowed aggregation, array and binary-string processing, simulation of concurrent swaps, and algorithmic complexity analysis.