45 lines
976 B
Markdown
45 lines
976 B
Markdown
---
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title: Integer to roman numeral
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tags: math,string
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cover: tram-car
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firstSeen: 2020-10-07T00:04:09+03:00
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lastUpdated: 2020-11-02T19:28:35+02:00
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---
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Converts an integer to its roman numeral representation.
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Accepts value between `1` and `3999` (both inclusive).
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- Create a lookup list containing tuples in the form of (roman value, integer).
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- Use a `for` loop to iterate over the values in `lookup`.
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- Use `divmod()` to update `num` with the remainder, adding the roman numeral representation to the result.
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```py
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def to_roman_numeral(num):
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lookup = [
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(1000, 'M'),
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(900, 'CM'),
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(500, 'D'),
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(400, 'CD'),
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(100, 'C'),
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(90, 'XC'),
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(50, 'L'),
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(40, 'XL'),
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(10, 'X'),
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(9, 'IX'),
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(5, 'V'),
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(4, 'IV'),
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(1, 'I'),
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]
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res = ''
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for (n, roman) in lookup:
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(d, num) = divmod(num, n)
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res += roman * d
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return res
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```
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```py
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to_roman_numeral(3) # 'III'
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to_roman_numeral(11) # 'XI'
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to_roman_numeral(1998) # 'MCMXCVIII'
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```
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