1p3a Question · Mar 2026

Uber SDE2 SDE3 Online Assessment Experience and Problems

Question Details

Today, I completed the Uber Online Assessment for an SDE-2/SDE-3 role. The assessment was conducted on HackerRank under strict proctoring (camera monitored) and consisted of 2 problems to be solved in

Full Details

Today, I completed the Uber Online Assessment for an SDE-2/SDE-3 role. The assessment was conducted on HackerRank under strict proctoring (camera monitored) and consisted of 2 problems to be solved in 90 minutes. Problem 1: Given a permutation of size n, we needed to construct a binary string of length n. For each k (1 ≤ k ≤ n), determine whether k is “balanced”. A value k is considered balanced if there exists a subarray [l, r] such that the elements in that subarray form a permutation of numbers from 1 to k.

Constraints: 1 ≤ n ≤ 2 × 10^5 Examples:

Input: [1, 3, 2, 4]

Output: "1011"

Input: [3, 1, 2, 4]

Output: "1111" --- Problem 2: We are given n plates placed on a 2D plane with coordinates defined by arrays x and y. Two plates can be collected together if: * They lie in the same row (same x) or same column (same y), and * Their distance is ≤ d The goal is to determine the minimum time required to collect all plates, where collecting one plate allows collecting all plates connected to it under these rules.

Constraints: 1 ≤ n ≤ 10^5 0 ≤ d ≤ 10^9 0 ≤ x[i], y[i] ≤ 10^9 Example: n = 3, d = 1 x = [0, 2, 1] y = [0, 1, 2]

Output: 3 --- Overall, the assessment focused heavily on efficient data structures and problem-solving under constraints (O(n log n) / O(n) solutions). It was a great experience working through these problems. I am able to solve both problems.

About This Question

This is a reported interview question from a uber interview for a swe role during the oa round reported in 2026.

It covers the following topics: Arrays, Backtracking, Strings .