Talk:Rep-string: Difference between revisions
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==Clarification== |
==Clarification== |
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The task needs some clarifation. What is a repeat? Is string "10" itself repeated once? Is string "101" a repeat of "10"? When finding a repeated substring "if any", what's the preferred answer for "1111", is it "1" or "11", or even "111" and "1111"? There needs be a clear definition of the word "repeat", not just relying on whatever the first sample solution says, beause can be too arbitrary. --[[User:Ledrug|Ledrug]] ([[User talk:Ledrug|talk]]) 03:53, 12 May 2013 (UTC) |
The task needs some clarifation. What is a repeat? Is string "10" itself repeated once? Is string "101" a repeat of "10"? When finding a repeated substring "if any", what's the preferred answer for "1111", is it "1" or "11", or even "111" and "1111"? There needs be a clear definition of the word "repeat", not just relying on whatever the first sample solution says, beause can be too arbitrary. --[[User:Ledrug|Ledrug]] ([[User talk:Ledrug|talk]]) 03:53, 12 May 2013 (UTC) |
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:I think I was most sloppy about ''"a series of ones and zeroes in a string"'': I meant a series of ones ''or'' zeroes. .. Oh wait .. Re-reading your question, repeat means "two or more times" which is in the description. |
:I think I was most sloppy about ''"a series of ones and zeroes in a string"'': I meant a series of ones ''or'' zeroes. .. Oh wait .. Re-reading your question, repeat means "two or more times" which is in the description. |
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:# If any valid Y is found then X is a rep-string. |
:# If any valid Y is found then X is a rep-string. |
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:Hope this helps :-) --[[User:Paddy3118|Paddy3118]] ([[User talk:Paddy3118|talk]]) 08:22, 12 May 2013 (UTC) |
:Hope this helps :-) --[[User:Paddy3118|Paddy3118]] ([[User talk:Paddy3118|talk]]) 08:22, 12 May 2013 (UTC) |
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::To answer the question: is "101" a repeat of "10"? Yes. Repeated (twice, and then truncated) to the original length of three. -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 07:22, 13 May 2013 (UTC) |
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::By the way, almost all programming examples have incorrect output, showing strings to be non-reps, whilest in fact, they are. -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 07:22, 13 May 2013 (UTC) |
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==Reason for update request== |
==Reason for update request== |
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Revision as of 07:22, 13 May 2013
Inspiration
The task was inspired by this question on stackoverflow. --Paddy3118 (talk) 19:45, 10 May 2013 (UTC)
Clarification
The task needs some clarifation. What is a repeat? Is string "10" itself repeated once? Is string "101" a repeat of "10"? When finding a repeated substring "if any", what's the preferred answer for "1111", is it "1" or "11", or even "111" and "1111"? There needs be a clear definition of the word "repeat", not just relying on whatever the first sample solution says, beause can be too arbitrary. --Ledrug (talk) 03:53, 12 May 2013 (UTC)
- I think I was most sloppy about "a series of ones and zeroes in a string": I meant a series of ones or zeroes. .. Oh wait .. Re-reading your question, repeat means "two or more times" which is in the description.
- Alternatively:
- Take a string of ones and zeroes X.
- Find out if there is at least one string Y of ones and/or zeroes that when repeated and truncated on the right to the same length as X is both equal to X and contains at least two repetitions of Y.
- If any valid Y is found then X is a rep-string.
- Hope this helps :-) --Paddy3118 (talk) 08:22, 12 May 2013 (UTC)
- To answer the question: is "101" a repeat of "10"? Yes. Repeated (twice, and then truncated) to the original length of three. -- Gerard Schildberger (talk) 07:22, 13 May 2013 (UTC)
- By the way, almost all programming examples have incorrect output, showing strings to be non-reps, whilest in fact, they are. -- Gerard Schildberger (talk) 07:22, 13 May 2013 (UTC)
Reason for update request
Ledrug posted a great algorithm for Python that worked on the previous list of examples but would have failed on a string of all ones or all zeroes without a (very) minor tweak. I applied the tweak but thought that:
'11' '00'
Should added to the list of mandatory test strings. --Paddy3118 (talk) 04:51, 13 May 2013 (UTC)