Consider the following pseudocode function.

Question

Consider the following pseudocode function.function Crunch(x R)
    
if x ≥ 100
then
 
    
return x/100
    
else
 
    
return x + Crunch(10 · x)
(a) Compute Crunch(6).
Crunch(6) = 1

(b) What happens if you try to compute Crunch(−25)? What does this suggest about an appropriate precondition for this function?

Answer 1

 

crunch(6) will return 6+crunch(60) = 6+60+crunch(600) = 6+60+6 = 72

 

 

crunch(-25) will endlessly cycle as  "x+crunch(10*x)" is repeatedly called and will likely crash whatever system it is running on once the stack is exhausted.   As a precondition, this function should reject inputs that are less than or equal to zero.