Assignment

Part 1:

In your program, write a method that accepts a positive integer and returns true if the number is a prime number and false otherwise. Note that 2 is the only even prime number. An odd integer is prime if it not divisible by any odd integer less than or equal to the square root of the number.

Part2:

A prime number whose reversal is also a prime number is called emirp. For example, 11, 13, 79 and 359 are emirps. Write a program that outputs to a ListBox the first 100 emirps. Your program must contain the method from Part 1 that returns true if a number is prime; false otherwise and another method that returns the reversal of a positive number. You can reverse the integer in the following way:

· Convert the integer into a string

value = num.ToString();

· Use the following code to reverse the integer

string newNum = "";

for (int l = value.Length; l > 0; l--)

newNum = newNum + value[l-1];

Also, your program should have a TextBox that will accept a positive integer from the user and then display whether the positive integer if an emirp.

In addition to using a ListBox for the output of the 100 emirps, also write these values to an output file. Add this as a method. You should use the values from the ListBox as output to the file.