Reviewing code logic/algorithm

Question

This:

Welcome to Code Review! I'm afraid this question does not match what this site is about. Code Review is about improving the cleanliness of existing, working code. Code Review is not the site to ask for help in fixing or changing what your code does. Once the code does what you want, we would love to help you do the same thing in a cleaner way! ^source

So when we say "Code Review is about improving the cleanliness of existing, working code", reviewers:

• clean the code
• simplify the code
• Change ugly variable names
• make the code more beautiful
• Provide best practices particular to the language
• more

Does changing code logic count? For example:

Your code is too slow, perhaps you can use a better algorithm for better performance.

//code with better performance

I'm curious because I didn't see that in answers I read. I didn't read them all, maybe some answers do. But is it on topic here?

Answer 1

No, we don't just rearrange code to make it prettier. Performance is specifically listed as one of our focus areas on What topics can I ask about here?

Many of our answers do address concrete performance issues. Sometimes those answers are in direct response to a request in the question. Other times we point out problems that the author didn't even know existed.

Examples:

• Collaboratively investigating a performance issue with multiple causes: Integer Partition using an iterator
• Effective use of input/output routines: toBase64 encoder
• Effective use of SQL: Creating an object oriented model in VBA using COM and ADODB from 2 depended SQL tables
• Optimization that requires a specialized data structure: Speed up counting sort algorithm in Ruby
• Text processing algorithm: Slowly working word counter
• Subtle pitfalls of implementing a sorting algorithm: Quicksort implementation in Python
• Replacing the whole sorting algorithm with a simpler one: A character array of arbitary length with 'R', 'B', 'W' is needed to be sorted in that order
• Performance comparison of regular expressions: Fast regex to extract strings before and after a time
• Squeezing more performance out of a string substitution function: Fastest way of removing a substring from a string
• Discussion about prime factoring strategies: Project Euler #3 - largest prime factor
• Discussing how Java and CPUs work, and doing microbenchmark comparisons: Efficiently checking if a number is divisible by 3

In particular, the performance, algorithm, complexity, and time-limit-exceeded tags all directly deal with increasing speed.

Answer 2

Nothing in the FAQ (sorry, Help Center) disqualifies changes to code logic as either something to seek in a question or something to offer in an answer.

From the Help Center guide to suitable topics:

• Best practices and design pattern usage
• Security issues
• Performance
• Correctness in unanticipated cases

Any one of those may involve a change to code logic, particularly Best Practices, which you also list.

I think at least half of my answers have suggested significant changes to logic and several of those questions explicitly requested it. Neither the questions nor my answers were closed. I am hardly the most prolific Code Review contributor but I do not think I am a rogue who just slipped through the net.

So Simon probably does just need some help, as has requested, with the wording.