CHAPTER: RECURSION

Question 1

Recursion

Answer 1

• when procedure or function calls itself

Question 2

Essential features of Recursion

Answer 2

• must have base case
• must have general case
• must unwind once base case is reached

Question 3

Why STACK appropriate for Recursion

Answer 3

• Last in first out
• each recursive call can push to stack and then popped as function ends
• enables unwinding to maintain required order

Question 4

Advantages of recursion

Answer 4

• produce simpler, more natural solutions to a problem

Question 5

Disadvs of recursion

Answer 5

• less efficient computer time, in storage space as lots used for states and return addresses
• could lead to inifinte recursion

Question 6

How computer translates recursive program code

Answer 6

before procedure call is execute, current state register stored onto stack
- when returning register reinstate one stack
- when bases case maet, algorithm unwinds
- the last set of values taken off the stack in reverse orderU

Question 7

Unwinding

Answer 7

• when base is reached all data stored in stack gets popped out from the top of the stack