Checkpoint: stacks, search, and intervals
Cold recall
Three problems from the last three units, rebuilt with no lesson above them.
Same rules as the last checkpoint. No looking at earlier submissions, and no reading the lesson the problem came from until you have finished or genuinely stalled.
One of these three is a monotonic stack, one is a binary search that is not over a sorted array, and one is a greedy interval selection. Deciding which is which before you type is the skill being tested.
Largest Rectangle in Histogram, cold
You have solved this one before. Rebuild it from scratch without looking at your old submission. If the approach does not come back within a few minutes, that is the signal that it needs another pass.
Koko Eating Bananas, cold
You have solved this one before. Rebuild it from scratch without looking at your old submission. If the approach does not come back within a few minutes, that is the signal that it needs another pass.
Non-overlapping Intervals, cold
You have solved this one before. Rebuild it from scratch without looking at your old submission. If the approach does not come back within a few minutes, that is the signal that it needs another pass.