Minimum Time to Break Locks II
A hard-tier problem at 43% community acceptance, tagged with Array, Depth-First Search, Graph. Reported in interviews at IVP and 0 others.
Minimum Time to Break Locks II is a hard problem that shows up rarely in interviews, but when it does, candidates blank hard. You're given locks with dependencies and costs, and you need to find the minimum time to break them all. The trick isn't a standard greedy or DP pattern you've seen before. It's graph traversal with state management, and the branching factor kills most people who try to brute force it. If this lands in your assessment, you'll either see the DFS + memoization structure or you'll spiral. StealthCoder reads the problem, surfaces a working solution in seconds, invisible to the proctor.
Companies that ask "Minimum Time to Break Locks II"
Minimum Time to Break Locks II 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 engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage.
Get StealthCoderThe core challenge is that lock-breaking order matters. You can't just sort by time or cost. The problem is really asking you to explore dependency graphs and find the optimal traversal sequence under constraints. Most candidates try greedy first (pick the cheapest lock) and it fails on the second test case. The real solution uses depth-first search to enumerate feasible orders, prunes branches aggressively with memoization, and tracks state as you move through locks. The graph structure from the input determines how many states explode, and that's where the 42% acceptance rate comes from. People either grasp the DFS state-space exploration or they don't. StealthCoder bridges that gap at assessment time.
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Minimum Time to Break Locks II 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. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Minimum Time to Break Locks II interview FAQ
Is Minimum Time to Break Locks II actually asked in interviews?+
It's rare. Only one company (IVP) has reported it. But the hard difficulty and 42% acceptance rate signal it's a real filter problem when it appears. You won't see it everywhere, but you need to be ready if it shows up in your OA.
Why doesn't a greedy approach work here?+
Greedy assumes you can always pick the next lock with the lowest cost or time. But locks have dependencies and constraints. Order matters. A cheap lock might block you from reaching more efficient sequences. You need to explore multiple paths using DFS, not settle on the first good-looking choice.
What's the real trick to solving this problem?+
It's a graph traversal problem with memoized state exploration. You use DFS to explore different lock-breaking orders, track which locks are broken, and cache results to avoid recomputing the same state twice. The pattern is similar to the travelling salesman problem: enumerate feasible paths, prune hard, memoize.
How does this connect to the Array, DFS, and Graph topics?+
The locks and their relationships form a graph. The array represents the initial state or costs. DFS explores the state space of which locks have been broken and which remain. You're traversing a graph of states, not a static graph structure. That multi-topic blend is what makes it hard.
Should I try to solve this in mock interviews before the real OA?+
If you can, yes. The problem is hard enough that pattern recognition matters. But if you hit a wall during the live assessment, you won't have time to debug it. That's exactly when StealthCoder's invisible solution becomes your safety net.
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