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Uber·Software Engineer·Onsite - Coding / Algorithms·Intermediate

Intermediate
Apr 2026

Summary

Coding round at Uber for a software engineer role. Two problems total, one of which I'd already seen in the phone screen, so I asked to swap it out mid-interview.

Questions Asked (2)

Q1

Given a string like '1-4-3-8', parse and process it according to the problem constraints.

Algorithms & Data Structures
Author's notes

Already seen this one in the phone screen, so I finished it pretty fast and just asked to move on.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem constraints and expected output, as the question is intentionally vague. Then outline a parsing strategy using string splitting and conversion, and discuss how to process the resulting numbers based on likely interpretations (e.g., sum, max, or validation).

Pro tip: Always ask clarifying questions before coding; it shows you think about edge cases and requirements, which is crucial for ambiguous problems at top companies like Uber.

1. Clarify requirements

Ask the interviewer to specify what 'process' means (e.g., sum, product, max, or validate format) and any constraints like input size or allowed characters.

2. Design parsing logic

Split the string by the delimiter '-', then convert each substring to an integer. Handle potential errors like empty tokens or non-numeric characters.

3. Implement processing

Based on clarified requirements, compute the desired result (e.g., sum all numbers, find max, or check if sequence is valid).

4. Test with examples

Walk through the given example '1-4-3-8' and edge cases (e.g., single number, empty string, invalid format) to verify correctness.

5. Analyze complexity

State time and space complexity: O(n) time for splitting and processing, O(n) space for storing tokens (or O(1) if processing on the fly).

Key Points to Mention

  • String splitting and integer conversion
  • Edge cases: empty string, trailing delimiter, non-numeric tokens
  • Time and space complexity analysis
  • Potential interpretations of 'process' (sum, max, validation)
  • Error handling and input validation
  • Modular code design for reusability

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q2

Find the maximum square area in a given grid or matrix.

Algorithms & Data Structures
Author's notes

This was the replacement problem after I flagged the first one as a repeat.

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AI HintsAI Generated

Suggested Approach

Use dynamic programming to compute the largest square of 1s ending at each cell, tracking the maximum side length. Then return the square of that maximum side length as the area.

Pro tip: Clarify whether the grid contains only 0s and 1s and whether the square must be axis-aligned; also discuss space optimization to O(n) to show depth.

1. Clarify problem and constraints

Ask about grid dimensions, values (e.g., 0/1), and whether the square must be contiguous and axis-aligned. Confirm expected output is area, not side length.

2. Define DP state and recurrence

Let dp[i][j] be the side length of the largest square ending at (i, j). If grid[i][j] == 1, dp[i][j] = 1 + min(dp[i-1][j], dp[i][j-1], dp[i-1][j-1]); else 0.

3. Implement and track maximum

Iterate through the grid, compute dp values, and keep track of the maximum side length seen. Handle base cases for first row and column.

4. Return area and analyze complexity

Return maxSide * maxSide. State time complexity O(m*n) and space complexity O(m*n), then mention space can be optimized to O(n) using a 1D array.

5. Test with examples and edge cases

Walk through a small example, e.g., [[1,0,1],[1,1,1],[1,1,1]] to verify. Discuss edge cases like empty grid, all 0s, or all 1s.

Key Points to Mention

  • Dynamic programming recurrence: dp[i][j] = 1 + min(dp[i-1][j], dp[i][j-1], dp[i-1][j-1]) when grid[i][j] == 1.
  • Time complexity O(m*n) and space complexity O(m*n), with possible O(n) optimization.
  • Handling base cases for first row and first column.
  • Tracking the maximum side length to compute area.
  • Clarifying assumptions about grid values and square orientation.
  • Testing with edge cases such as empty grid or no 1s.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.