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66 lines
1.6 KiB
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66 lines
1.6 KiB
Markdown
---
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layout: post
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title: "Find Substrings for line Encoding [CF]"
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date: 2016-06-11 03:04:23 +0700
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categories: [python, codefights]
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---
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Given a string, return its encoding defined as follows:
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First, the string is divided into the least possible number of disjoint **substrings** consisting of identical characters
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for example, `"aabbbc"` is divided into `["aa", "bbb", "c"]`
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Next, each substring with length greater than one is replaced with a concatenation of its length and the repeating character
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for example, substring `"bbb"` is replaced by `"3b"`
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Finally, all the new strings are concatenated together in the same order and a new string is returned.
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#### SUBSTRING
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A **substring** of a string `S` is another string `S'` that occurs in `S`. For example, `"Fights"` is a substring of `"CodeFights"`, but `"CoFi"` isn't.
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**Example**
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For `s = "aabbbc"`, the output should be `lineEncoding(s) = "2a3bc"`.
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**Input/Output**
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* [time limit] 4000ms (py)
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* [input] string s (String consisting of lowercase English letters.)
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_Constraints:_ `4 ≤ s.length ≤ 15.`
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* [output] string (Encoded version of s.)
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**Solution:**
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```python
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import re
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def lineEncoding(s):
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grub = [ m.group(0) for m in re.finditer(r"(\w)\1*", s )]
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numb = 0
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out = []
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for i in grub:
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numb += 1
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if len(i) > 1:
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out.append(grub[numb-1].replace(grub[numb-1], str(len(i))+i[0]))
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else:
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out.append(i)
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return ''.join(out)
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```
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**Result Tests:**
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```python
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>>>
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s = "aabbbc"
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>>> lineEncoding(s)
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"2a3bc"
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>>>
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>>> s = "abbcabb"
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>>> lineEncoding(s)
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"a2bca2b"
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>>>
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>>> s = "abcd"
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>>> lineEncoding(s)
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"abcd"
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>>>
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``` |