Write a program that asks the user to enter n, an odd integer between 3 and 39 (your program should check both that the number is odd and that it is in the designated range).

This is an example of input validation.

HINT: use a while loop.



   // (1) Read an integer from the user

   // (2) Check to see if it's valid

   // (3) If not valid, read an integer from the user again
   //        and loop back up to step (2)




















Next, your program uses a loop to display a triangle.

The top row of the triangle should have 20 spaces followed by a single '*' character.  The next row should have 19 spaces followed by three '*' characters.  The next row should have 18 spaces followed by five '*' characters.  And so on until a row of n '*' characters is printed.

For example, if the user entered 5, the triangle would look like this:

                    *
                   ***
                  *****

If the user entered 11, the triangle would look like this

                    *
                   ***
                  *****
                 *******
                *********
               ***********

Use nested loops (not just a bunch of hard-coded cout lines!).

If you're having trouble, write the program in stages.  First get the correct number of '*' characters printing on each line, then work on the spacing.