Minimum Operations to Make Columns Strictly Increasing
A easy-tier problem at 72% community acceptance, tagged with Array, Greedy, Matrix. Reported in interviews at IBM and 0 others.
You're staring at a matrix and you need to make each column strictly increasing by changing numbers. It sounds straightforward until you realize the greedy choices you make in one column affect your options in the next. IBM has asked this. With a 72% acceptance rate, the problem looks easy on the surface, but candidates miss the greedy insight on first read. If this problem hits your live assessment and you freeze on the strategy, StealthCoder surfaces a working solution in seconds, invisible to the proctor.
Companies that ask "Minimum Operations to Make Columns Strictly Increasing"
Minimum Operations to Make Columns Strictly Increasing is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop.
Get StealthCoderThe trap is thinking you can solve each column independently. You can't. The greedy move is to process columns left to right and track the minimum value you must use in the current column based on what you placed in the previous column. Once you see that pattern, the Array and Greedy framing clicks: for each element, you either keep it or increment it to the smallest value that's greater than the element above it. The Matrix topic is a hint that you're iterating through rows and columns in a specific order. Common pitfall: trying to minimize operations locally without considering downstream constraints. StealthCoder's role here is insurance if you spend live time chasing a wrong approach and need the correct greedy sequence instantly.
Pattern tags
You know the problem.
Make sure you actually pass it.
Minimum Operations to Make Columns Strictly Increasing recycles across companies for a reason. It's easy-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Minimum Operations to Make Columns Strictly Increasing interview FAQ
Is this really easy or is the acceptance rate misleading?+
The 72% acceptance rate is genuine. Once you lock the greedy insight (go left to right, force each column value higher than the previous), implementation is straightforward. The trick is reaching that insight, not the code itself. Most who fail miss the column dependency.
Do I need to use dynamic programming here?+
No. This is a Greedy problem dressed up in Matrix language. DP would overkill it and waste time. A single pass left to right with greedy choice per element is the intended solution. The Array and Greedy tags are your signal.
What's the most common mistake candidates make?+
Trying to solve each column as an independent optimization. That breaks because column i's values constrain column i+1. You must process columns in order and propagate the minimum constraint forward. Candidates who skip that step run into failures mid-way through test cases.
How does the Greedy approach actually work on this matrix?+
For each element, decide: keep it, or increment it to meet the strictly increasing constraint from the row above. Track the minimum value you place in each row position. That minimum becomes the floor for the next column. Forward pass, greedy choice per cell, done.
Is this still asked in real interviews or just IBM?+
IBM is the reported source in the data. Lower frequency asks overall. That said, the Array and Greedy pattern appears across tech companies, so the underlying skill is worth understanding. Expect it less often than classic greedy matrix problems.
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