Mumbling
CodeWars/Mumbling
#Exercise :
This time no story, no theory. The examples below show you how to write function accum:
accum("abcd") // -> "A-Bb-Ccc-Dddd"
accum("RqaEzty") // -> "R-Qq-Aaa-Eeee-Zzzzz-Tttttt-Yyyyyyy"
accum("cwAt") // -> "C-Ww-Aaa-Tttt"