Kata

A number is self-descriptive when the n'th digit describes the amount n appears in the number.

Example:

For the number 21200:

• There are two 0's in the number, so the first digit is 2.
• There is one 1 in the number, so the second digit is 1.
• There are two 2's in the number, so the third digit is 2.
• There are no 3's in the number, so the fourth digit is 0.
• There are no 4's in the number, so the fifth digit is 0.

Numbers can be of any length up to 9 digits and are only full integers. For a given number, derive a function that returns:

• True if the number is self-descriptive
• False if the number is not.