Solve odd-string, digit swap, patient slot assignment
Company: DRW
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Take-home Project
##### Question
Task 1 – Odd-occurrence string: Write a function that, given an integer N (1..200
000), returns a length-N lowercase string in which every letter that appears occurs an odd number of times.
Task 2 – Min-swap closest numbers: Write a function solution(string S, string T) that, given two digit strings S and T of equal length N (1..100
000) with no leading zeros, returns the minimum number of position-wise digit swaps needed to minimize |int(S) – int(T)|.
Task 3 – Patient slot assignment: Write a function solution(int[] A, int[] B, int S) that, given two arrays A and B of length N (1..100
000) containing preferred doctor-appointment slots (1..S, where S ≤ 100
000) for each patient, returns true if all patients can be assigned one of their two preferred slots with no slot shared by more than one patient, otherwise false.
Quick Answer: This multi-part problem evaluates string manipulation and parity/combinatorics for constructing odd-occurrence strings, greedy optimization and minimal-change reasoning for digit-swap distance minimization, and bipartite matching/assignment skills for patient slot allocation.