London | 25-SDC-July | Rihanna Poursoltani | Sprint 2 | Improve code with caches#88
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RihannaP wants to merge 1 commit intoCodeYourFuture:mainfrom
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London | 25-SDC-July | Rihanna Poursoltani | Sprint 2 | Improve code with caches#88RihannaP wants to merge 1 commit intoCodeYourFuture:mainfrom
RihannaP wants to merge 1 commit intoCodeYourFuture:mainfrom
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RihannaP
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📅 Sprint 2
cjyuan
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Feb 15, 2026
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Array creation is a relatively costly operation.
From line 41, we know coins can only be one of the following 8 arrays:
[200, 100, 50, 20, 10, 5, 2, 1]
[100, 50, 20, 10, 5, 2, 1]
[50, 20, 10, 5, 2, 1]
...
[1]
We could further improve the performance if we can
- avoid repeatedly creating the same sub-arrays at line 41 (e.g. use another cache), and
- create key as (total, a_unique_integer_identifying_the_subarray) instead of as (total, tuple of coins)
- There are only a small number of different subarrays. We can map each subarray to a unique integer.
Can you implement this?
cjyuan
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