ALL CODE MUST BE WRITTEN USING RECURSION

* Write a method called countdown(int num), it should print out every number from num to 0.

* Write a method, called sumDigits(int n). Given a non-negative int n, return the sum of its digits recursively (no loops).

sumDigits(126) 9 sumDigits(49) 13 sumDigits(12) 3

*

Given base and n that are both 1 or more, compute recursively the value of base to the n power, so powerN(3, 2) is 9 (3 squared).

powerN(3, 1) 3

powerN(3, 2) 9

powerN(3, 3) 27

*

Write a method, count7(int). Given a non-negative int n, return the count of the occurrences of 7 as a digit, so for example 717 yields 2. (no loops).

count7(717) 2

count7(7) 1

count7(123) 0