C$++$

Option $2$: The local t$-$shirt shop sells shirts that retail for $$12.$ Quantity dis$-$ counts are given as follow:

Number of Shirts Discount

$51010\%112015\%213020\%31$ or more $25\%$

Write a program that prompts the user for the number of shirts required and then computes the total price. Make sure the program accepts only nonnegative input.

Use the following sample runs to guide you:

Sample Run $1$:

How many shirts would you like $?$

$4$

The cost per shirt is $$12$ and the total cost is $$48$

Sample Run $2$:

How many shirts would you like $?$

$0$

The cost per shirt is $$12$ and the total cost is $$0$

Sample Run $3$:

How many shirts would you like $?$

$8$

The cost per shirt is $$10\mathrm{.}80$ and the total cost is $$86\mathrm{.}40$

Sample Run $4$:

How many shirts would you like $?$

$-2$

Invalid Input: Please enter a nonnegative integer