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NW | 26-SDC-Mar | TzeMing Ho | Sprint 2 | improve with precomputing - #172

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NW | 26-SDC-Mar | TzeMing Ho | Sprint 2 | improve with precomputing#172
TzeMingHo wants to merge 4 commits into
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TzeMingHo:coursework/improve_with_precomputing

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@TzeMingHo

@TzeMingHo TzeMingHo commented Jun 21, 2026

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Learners, PR Template

Self checklist

  • I have titled my PR with Region | Cohort | FirstName LastName | Sprint | Assignment Title
  • My changes meet the requirements of the task
  • I have tested my changes
  • My changes follow the style guide

Changelist

I have attempted with sorted and set

@TzeMingHo TzeMingHo added 📅 Sprint 2 Assigned during Sprint 2 of this module Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. labels Jun 21, 2026
cjyuan
cjyuan reviewed Jun 22, 2026
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@cjyuan cjyuan left a comment

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Code looks good.

Could you use Big O notation to quantify the improvement achieved by the new implementation? A brief comparison of the time complexity before and after the change would be helpful.

@cjyuan cjyuan added Reviewed Volunteer to add when completing a review with trainee action still to take. and removed Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. labels Jun 22, 2026
@TzeMingHo TzeMingHo added Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. and removed Reviewed Volunteer to add when completing a review with trainee action still to take. labels Jun 23, 2026
cjyuan
cjyuan reviewed Jun 23, 2026
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Comment thread Sprint-2/improve_with_precomputing/common_prefix/common_prefix.py Outdated
return longest

# before changes, it was N^2, bacause it got a for loop inside a for loop
# after changes, it is N + N. The first N for sorted, and another N for the loop.

@cjyuan cjyuan Jun 23, 2026

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Could you lookup the complexity of sorted() in Python?

@TzeMingHo TzeMingHo Jun 23, 2026

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The worst case for sorted is NlogN, when the list is randomly ordered.

@cjyuan cjyuan Jun 23, 2026

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O(n log n) is the optimal average-case time complexity achievable by any comparison-based sorting algorithm.

An O(n) complexity approach is possible but that would involve writing a lot of code. 😄

@cjyuan cjyuan added Reviewed Volunteer to add when completing a review with trainee action still to take. and removed Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. labels Jun 23, 2026
@TzeMingHo TzeMingHo added Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. and removed Reviewed Volunteer to add when completing a review with trainee action still to take. labels Jun 23, 2026
@cjyuan cjyuan added Complete Volunteer to add when work is complete and all review comments have been addressed. and removed Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. labels Jun 23, 2026
@illicitonion

illicitonion commented Jun 30, 2026

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Closing PR because the SDC run has finished. Feel free to re-open if you're still working on it.

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