Practice Recursion

Questions:

1.- What is a recursion?

2.- In this code:

function factorial (n is a non-negative integer)

if n is 0 then

return 1 [by the convention that 0! = 1]

else

return factorial(n – 1) times n [recursively invoke factorial with the parameter 1 less than n]

end if

end function

When n=4, how many times the function is re-executed? (Not counting the first time is called, only the recursions)

3.- State the operations that the last program makes, for example, the first line of operation would be:

factorial(4-1) times 4 --> 3!*4

Continue...

Answers:

1.- A function that calls itself as a part of a process dividing the tasks in more little and little tasks.

2.- 4 times.

3.-

factorial(4-1) times 4 --> 3!*4

factorial(3-1) times 3 --> 2!*3

factorial(2-1) times 2 --> 1!*2

factorial(1-1) times 1 --> 0!*1

#recursion