ctucker / telephone

Phone Numbers kata, from Emily Bache's Coding Dojo Handbook

Telephone

Given a list of phone numbers, determine if it is consistent. In a consistent phone list no number is a prefix of another. For example:

• Bob: 91125426
• Alice: 97 625 992
• Emergency: 911

In this case, it is not possible to call Bob because the phone exchange would direct your call to the emergency line as soon as you dialled the first three digits of Bob's phone number. So this list would not be consistent.

The input to your system will be a map of name to phone number. Names therefore cannot repeat (i.e. you don't have to deal with disambiguation). The output should be a boolean value: true if the list of phone numbers is consistent, false otherwise.

Extensions

Report back which entries are in conflict: "Bob @ 91125426" is unreachable because of "Emergency @ 911"

Add the ability to parse the phone number list from a text file in

<name> : <number> form

Credit

Cribbed from Emily Bache's "Coding Dojo Handbook"