The number 10213223 is self-descriptive. Count the number of zeros, ones, twos, and threes that are contained in this number and you have 1 zero, 2 ones, 3 twos, 2 threes, but that is a replica of the number itself 10|21|32|23.
Write a function that returns true if its argument is a self-descriptive number, false if not.
selfDescriptive("22") ➞ true
selfDescriptive("3999") ➞ false
selfDescriptive("31331419") ➞ true
selfDescriptive("21321316") ➞ false
selfDescriptive("4132232416171") ➞ false
selfDescriptive("31331819") ➞ true71322723161814151019 (see Resources tab).