Question

For the recursive method below, list the base case and the recursive statement, then show your work for solving a call to the recur() method using any parameter value 10 or greater.

public static int recur(int n)
{
if(n < 1)
{
return 3;
}
else
{
return recur(n / 5) + 2;
}
}

Answer 1

(a): The base case: if(n<1)

(b): The recursive statement: recur(n / 5)

(c): Parameter 10 returns 7

Step-by-step explanation:

Given

The above code segment

Solving (a): The base case:

The base case is that, which is used to stop the recursion. i.e. when the condition of the base case is true, the function is stopped.

In the given code, the base case is:

if(n<1)

Solving (b): The recursive statement:

The recursive statement is the statement within the function which calls the function.

In the given code, the recursive statement is:

recur(n / 5)

Solving (c): A call to recur() using 10

The base case is first tested

if (n < 1); This is false because 10 > 1

So, the recursive statement is executed

recur(n/5) +2=> recur(10/5)+2 => recur(2)+2

2 is passed to the function, and it returns 2

if (n < 1); This is false because 2 > 1

So, the recursive statement is executed

recur(n/5) +2=> recur(2/5)+2 => recur(0)+2

2 is passed to the function, and it returns 2

if (n < 1); This is true because 0 < 1

This returns 3

So, the following sum is returned

Returned values = 2 + 2 + 3

Returned values = 7