LeetCode 621 ·
Medium
Task Scheduler
Given task counts and a cooldown n between identical tasks, return the minimum total intervals.
Try it
Step through the core mechanic. The simulator below runs the greedy shape this problem is built on.
Walk the pattern
No dedicated step-through for this one yet. The shape is Greedy — its pattern page has the interactive walkthrough, the reference implementation, and a five-problem progression that this problem sits inside.
The approach
The most frequent task dictates the frame: (maxCount−1)·(n+1) slots, plus the number of tasks tied for the max. The answer is max(that frame, total tasks) — idle only when tasks cannot fill the gaps.
| Aspect | Value |
|---|---|
| Pattern | Greedy |
| Recognise it by | Schedule with a cooldown — fill gaps around the busiest task. |
| Time complexity | O(n) |
| Space complexity | O(1) |
| Difficulty | Medium |
Who asks it
Companies known to ask this problem, from public LeetCode company-tag aggregations. A signal of where to expect it, not a guarantee.