PLEASE WRITE IN JAVA and try to explain the code

Problem 1 Implement a recursive method printDigits that takes an integer num as a parameter and prints its digits in reverse order, one digit per line.

Problem 2 Design and implement a program that implements Euclids algorithm for finding the greatest common divisor of two positive integers. The greatest common divisor is the largest integer that divides both values without producing a remainder. An iterative version of this method was part of the RationalNumber class presented in Chapter 6. In a class called DivisorCalc, define a static method called gcd that accepts two integers, num1 and num2. Create a driver to test your implementation. The recursive algorithm is derived as follows: - gcd(num1, num2) is num2 if num2<=num1 and num2 divides num1 - gcd(num1, num2) is gcd(num2, num1) if num1

Problem 3 "Design and implement a recursive program to determine and print the Nth line of Pascal's Triangle, as shown below. Each interior value is the sum of the two values above it. Hint: use an array to store the values on each line."

1

1 1

1 2 1

1 3 3 1

1 4 6 4 1

1 5 10 10 5 1

1 6 15 20 15 6 1

1 7 21 35 35 21 7 1

1 8 28 56 70 56 28 8 1