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Given a string of Roman numerals, decide whether it forms a valid Roman number. If not, output the substring that proves this, from the list of 50 strings described below. Relevant fact This chal...
Given a sequence of letters, output only the vowels. Input A sequence of letters This may be a string or any ordered data structure of characters (provided it is consistent between inputs) Th...
Given a positive integer as input, indicate which base from 2 to 16 gives the most holes in the representation of the input in that base. The digits used are 0123456789ABCDEF. Note that these incl...
Given a sequence of letters, omit those with the highest or lowest pop count. Terminology The pop count or population count of a binary string is the number of 1s in it. For this challenge, the ...
Given a string of printable ASCII characters, convert them all to lowercase, except not just the letters. ASCII characters that are letters have a bit in their binary representation that is 0 for ...
Given a single character, which is a valid Roman numeral, output its value. Values There are 7 valid single character Roman numerals, with the following values: Character Value I...
Given a positive integer, count its odd digits. Input An integer from 1 to 999,999,999, inclusive, in any of the following formats: A number (such as an integer or floating point number), li...
