Solution: 2017 Fall Midterm - 15
Author: Michiel SmidQuestion
$\newcommand{\Hello}{{\rm H {\scriptsize ELLO}}}
\newcommand{\elsesp}{\phantom{\mathbf{else}\ }}$
Consider the recursive algorithm $\Hello$, which takes as input an integer $n \geq 0$:
(see document for missing code)
If you run algorithm $\Hello(5)$, how many times is the word "hello" printed?
(a)
16
(b)
15
(c)
14
(d)
13
Solution
We can draw a recursive tree to see how many times the word \enquote{hello} is printed.
Each time HELLO is called, \enquote{hello} is printed once. We can count the number of times HELLO is called
After counting, we see that \enquote{hello} is printed 15 times.