Kata

Isograms

An isogram (also known as a "nonpattern word") is a logological term for a word or phrase without a repeating letter.

Isograms can be useful as keys in ciphers, since isogram sequences of the same length make for simple one-to-one mapping between the symbols. Ten-letter isograms like PATHFINDER, DUMBWAITER, and BLACKHORSE are commonly used by salespeople of products where the retail price is typically negotiated, such as used cars, jewelry, or antiques.

For example, using the PATHFINDER cipher, P represents 1, A represents 2 and so on. The price tag for an item selling for $1200 may also bear the cryptic letters FRR, written on the back or bottom of the tag. A salesman familiar with the PATHFINDER cipher will know that the original cost of the item was $500.

(source: https://en.wikipedia.org/wiki/Isogram)

Task

Complete the functions, in order to encode/decode the input numbers/codes with the provided isogram keys, by mapping each letter to the numbers like this:

P A T H F I N D E R
1 2 3 4 5 6 7 8 9 0

The encode function should accept a non-negative number in integer or string format, and a key. The output of the function should be an uppercase string of letters.

The decode function should accept a code as a string of letters, and a key. The output of the function should be a number as a string.

Note: the key may be provided in upper- or lowercase

Return "Incorrect key or input!" in the following cases:

• the input number of the encode function is not an integer; or it's not in integer or string format; or it's negative;
• the input code of the decode function is not a string; or it's not made up of letters;
• the key has invalid length (≠ 10); or has repeated letters;
• not all the letters of code are available in key;
• one or both of the inputs are missing

Examples

Encoding:

 500,  "PATHFINDER"  -->  "FRR"
"500", "PATHFINDER"  -->  "FRR"
 1234, "PATHFINDER"  -->  "PATH"
 5.1,  "PATHFINDER"  -->  "Incorrect key or input!"
-500,  "PATHFINDER"  -->  "Incorrect key or input!"
 500,  "PATHFIND"    -->  "Incorrect key or input!"
 500,  "PATHFINDEE"  -->  "Incorrect key or input!"

Decoding:

"FRR", "PATHFINDER"  -->  "500"
 500,  "PATHFINDER"  -->  "Incorrect key or input!"
"500", "PATHFINDER"  -->  "Incorrect key or input!"
"FRR", "PATHFIND"    -->  "Incorrect key or input!"
"FRR", "PATHFINDEE"  -->  "Incorrect key or input!"
"LOL", "PATHFINDER"  -->  "Incorrect key or input!"

See some more examples in the sample tests.

---

My other katas

If you enjoyed this kata then please try my other katas! :-)

Translations are welcome!