Max Total Area
Reported by candidates from Amazon's online assessment. Pattern, common pitfall, and the honest play if you blank under the timer.
Amazon's April 2024 OA included Max Total Area, a geometry and optimization problem that hits candidates harder than they expect. You're likely looking at a scenario where you need to compute the maximum area from a set of rectangles, regions, or coordinates. The trap is thinking brute force will pass. It won't. StealthCoder is your safety net if the optimal approach doesn't land on the first attempt during the live assessment.
Pattern and pitfall
Max Total Area typically requires you to either find the largest single rectangle, merge overlapping regions, or select non-overlapping shapes to maximize cumulative area. The naive approach (check every combination) fails on larger inputs. The pattern usually demands a sweep algorithm, dynamic programming, or a greedy selection with coordinate compression. Common mistakes include not handling edge cases like touching-but-non-overlapping rectangles, or miscalculating area when coordinates aren't axis-aligned. The key insight is often that you can reduce 2D problems to 1D or that sorting and processing in a specific order unlocks the solution. StealthCoder reads the constraints and coordinates on your screen and surfaces the right decomposition in real time.
Memorize the pattern. If you can't, run StealthCoder. The proctor sees the IDE. They don't see what's behind it.
You can drill Max Total Area cold, or you can hedge it. StealthCoder runs invisibly during screen share and surfaces a working solution in under 2 seconds. The proctor sees the IDE. They don't see what's behind it. Made by an engineer who treats the OA as theater. If yours is tonight, you don't have time to grind. You have time to hedge.
Get StealthCoderRelated leaked OAs
This OA pattern shows up on LeetCode as maximal rectangle. If you have time before the OA, drill that.
You've seen the question.
Make sure you actually pass Amazon's OA.
Amazon reuses patterns across OAs. Made by an engineer who treats the OA as theater. If yours is tonight, you don't have time to grind. You have time to hedge. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Max Total Area FAQ
Is this really asking for total area of overlapping rectangles, or just the max single rectangle?+
Read the problem statement carefully. If it says 'max total area' and you have multiple shapes, it's usually asking for the sum of non-overlapping selections or the union of merged regions. If unclear during the OA, assume you need to handle overlaps by merging or subtracting. The problem title is your first clue.
Do I need coordinate compression for this problem?+
Possibly. If the coordinates are large (e.g., up to 10^9) but the number of rectangles is small (under 1000), coordinate compression lets you work on a smaller grid. Without it, you'll run out of memory or time. Check the constraints in the problem statement.
What's the trick with overlapping rectangles?+
The standard trick is to use a sweep line algorithm (often vertical or horizontal) combined with an interval merge or segment tree. You process rectangles in sorted order and track active intervals. This avoids checking every pair explicitly and runs in O(n log n) instead of O(n^2).
Should I try greedy, or is this definitely DP?+
Greedy works if you can prove sorting by one dimension (e.g., x-coordinate, area size) and picking non-overlapping shapes in that order gives the optimal answer. If the greedy choice at each step doesn't guarantee the global optimum, you'll need DP or backtracking. Test on the provided examples to see which holds.
How do I know if my solution is fast enough in 30-45 minutes?+
If you're iterating over all pairs of rectangles, that's O(n^2) and will fail for n > 5000. Aim for O(n log n) or better. If you've sorted and used a sweep or DP pass, you're likely in safe territory. Run through the complexity analysis in your head before submitting.