IT 117: Intermediate to Scripting
Answers to Class 24 Ungraded Quiz

  1. What do you call a function that calls itself? 
    a recursive function
  2. What two things must be true about a recursive algorithm for it to work? 
    there must be a condition under which recusion will stop
the recursive call must approach this condition
  3. What do call the situation where a function calls itself directly? 
    direct recursion
  4. What do you call the situation where a function calls another function, which then calls the original function? 
    indirect recursion
  5. Can you rewrite any recursive function using a loop instead of recursion? 
    yes
  6. Which is more efficient, a recursive algorithm or a non-recursive algorithm that does the same thing? 
    a non-recursive algorithm
  7. Write a recursive function that counts down from some number. In other words, this function prints it's argument, than all numbers down to 1. 
    def count_down(num):	
    print(num)
    if num > 1:
        count_down(num - 1)
  8. Write a recursive function that calculates the factorial of a number. 
    def factorial(num):
    if num == 1:
        return 1
    else:
        return factorial(num -1) * num