Debrief: read your own results

What the different failure modes mean, and what to do about each.

Keep the notes

Write down which of the four failure modes you hit and on which problem. That page is worth more than any individual solution, because the same mode will recur and you will recognize it faster.

Quick check· 5 min

Time allocation

Twenty minutes into a 45 minute problem you have a correct O(n squared) approach and a vague sense that an O(n log n) one exists. What is the best move?

Say the quadratic approach and its cost out loud, start writing it, and mention that a better bound probably existsKeep thinking about the faster approach, since a quadratic solution will not passWrite the quadratic one silently and only mention the faster idea if it finishes earlyAsk for a hint toward the faster approach before writing anything

Select all that apply· 5 min

Which units carry the second half?

Select every unit whose material the remaining units depend on directly.

Recursion and trees, since backtracking and memoized recursion are both built on itHeaps, since the weighted graph algorithms need a priority queueArrays and hashing, since visited sets and memo tables are hash structuresIntervals, since graph traversal is an interval problemBinary search, since every dynamic programming table is searched

Checkpoint: midpoint mock round

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Checkpoint: midpoint mock roundLesson 5 of 5About 19 min

Debrief: read your own results

What the different failure modes mean, and what to do about each.

Keep the notes

Write down which of the four failure modes you hit and on which problem. That page is worth more than any individual solution, because the same mode will recur and you will recognize it faster.

Quick check· 5 min

Time allocation

Twenty minutes into a 45 minute problem you have a correct O(n squared) approach and a vague sense that an O(n log n) one exists. What is the best move?

Select all that apply· 5 min

Which units carry the second half?

Select every unit whose material the remaining units depend on directly.