Minimum Time to Eat All Grains
A hard-tier problem at 39% community acceptance, tagged with Array, Two Pointers, Binary Search. Reported in interviews at Confluent and 0 others.
Minimum Time to Eat All Grains is a hard array problem that shows up in technical assessments at places like Confluent. You're given grains at different positions and a starting point. The catch is you can only move in one direction at a time, and you need to find the minimum total time to visit every grain position. Most candidates see the greedy trap first, pick the wrong direction, and waste the entire attempt. If this one blindsides you during a live OA, StealthCoder surfaces a working solution invisibly while you stay locked in.
Companies that ask "Minimum Time to Eat All Grains"
Minimum Time to Eat All Grains 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. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too.
Get StealthCoderThe trick here is that you can't just pick a direction and go. You have to consider the cost of backtracking. If grains span left and right of your start, you'll eventually have to go one way, come back, then go the other way. The binary search angle comes in when you're trying to optimize which direction to prioritize first. The two-pointer pattern lets you efficiently calculate the time for each possible strategy. A naive greedy approach fails because it doesn't account for the total backtracking cost across all positions. This is where the problem bites: the optimal solution isn't intuitive, and if you haven't drilled the backtracking-cost pattern before, you'll overthink it live. StealthCoder is your safety net if you hit this wall during the assessment.
Pattern tags
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Minimum Time to Eat All Grains recycles across companies for a reason. It's hard-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. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Minimum Time to Eat All Grains interview FAQ
Is this problem really hard or just confusing?+
It's hard because the trick isn't obvious. The acceptance rate is under 40 percent, which means most attempts fail at the algorithmic level, not the code level. The pattern is backtracking cost optimization, which isn't something you see every week.
What's the gotcha most candidates fall into?+
Greedy fails here. Picking the closest grain or going in one direction doesn't minimize time. You have to account for the cost of visiting grains on both sides and which order minimizes total distance traveled, including backtracks.
How do binary search and two pointers both fit this problem?+
Two pointers narrow down grain ranges. Binary search can optimize the decision of which direction to go first by testing different split points. Together they reduce redundant calculations and scale the solution efficiently.
Is Confluent the only company asking this?+
The data shows Confluent as the named source. It may appear elsewhere, but there's low frequency of public reports. This is the kind of problem that shows up in interviews at companies that care about optimization under constraints.
How much time should I spend drilling this before an OA?+
If you haven't seen the backtracking-cost pattern, this is a dangerous blind spot. One solid practice run with the solution explanation is worth it. But if it shows up live and you're stuck, that's what StealthCoder is for.
Want the actual problem statement? View "Minimum Time to Eat All Grains" on LeetCode →