$6.$ Programming Task $3$

For this task, you should implement a recursive function that gets $3$

parameters and return a string that is made of the first two input parameters

repeatedly. This means the output contains the first input followed by the

second input, followed by the first input again, $.....$The number of repetition of

the input strings is specified by the third argument of the method.

Here are some examples:

interlace$($Hello $,$World $,0)$ returns $$

interlace$($Hello $,$World $,1)$ returns $$Hello $$

interlace$($Hello $,$World $,2)$ returns $$Hello World $$

interlace$($Hello $,$World $,3)$ returns $$Hello World Hello$$

The name of the method is interlace and the header of the method was

written for you in Lab$2.$java.

$7.$ Programming Task $4$

In this task, you are required to write a recursion that gets a string and two

characters and returns the substring that is enclosed in two given characters.

You can assume that the given string includes only one instance of each

enclosing characters.

For example, where the input string is This is $[$quite$\}$ an example! and the first

enclosing character is $\text{'}[\text{'}$ and the second is $\text{'}\}\text{'},$ it should return quite.

The name of the method is getSubstring and the header of the method was

written for you in Lab$2.$java.

$8.$ Programming Task $5$

For this task, you need to write a recursion that converts a positive integer

including zero, to its binary equivalence. This method gets one integer input.

A binary form of an integer is calculated by repeatedly dividing the integer

number $($and later, its quotient$)$ by $2.$ You keep doing the division until the

quotient is zero. The reminders of the divisions, from the last division to the

first, form the binary representation of the integer number. Let$$s see an

example in which $23$ is converted to a binary number. R stands for the

remainder.

$23/2=11$ R $1$

$11/2=5$ R $1$

$5/2=2$ R $1$

$2/2=1$ R $0$

$1/2=0$ R $1$

Therefore, the binary representation of $23$ is $10111.$