Problem 3: Write a recursive function getGCD to calculate the greatest common denominator of two given numbers. For example, getGCD( 12, 9) = 3. The function should have the following declaration: function gcd = getGCD( n1, n2) where inputs n1 and n2 are positive integers and output gcd is the greatest common denominator of n1 and n2. The function should have a description. When the inputs are not positive integers, set the output to be a string 'Error' and use return to exit the function. (a) Set p3a = evalc('help getGCD').

Write a method named addall that could be placed inside the hashintset class. this method accepts another hashintset as a parameter and adds all elements from that set into the current set, if they are not already present. for example, if a set s1 contains [1, 2, 3] and another set s2 contains [1, 7, 3, 9], the call of s1.addall(s2); would change s1 to store [1, 2, 3, 7, 9] in some order. you are allowed to call methods on your set and/or the other set. do not modify the set passed in. this method should run in o(n) time where n is the number of elements in the parameter set passed in.