I would like actual solutions. Many thanks.

. Correctly compiles under the UNIX command line. When run from the command line your program must read from standard input an NPN formula. You can assume there is a space between every operator and number. Every number will be a 32 bit non-negative integer. Your program should be able to correctly handle the binary operators: +, -, X. IMPORTANT: be careful that your program recognises precisely the three characters above (plus sign, minus sign, and the lowercase letter x, respectively). O Other examples of NPN formulas are: 3 ( result is 3) x 2 O (result is 0) x + 2 3 + 2 2 (result is 20) + x 2 3 4 (result is 10) . Correctly compiles under the UNIX command line. When run from the command line your program must read from standard input an NPN formula. You can assume there is a space between every operator and number. Every number will be a 32 bit non-negative integer. Your program should be able to correctly handle the binary operators: +, -, X. IMPORTANT: be careful that your program recognises precisely the three characters above (plus sign, minus sign, and the lowercase letter x, respectively). O Other examples of NPN formulas are: 3 ( result is 3) x 2 O (result is 0) x + 2 3 + 2 2 (result is 20) + x 2 3 4 (result is 10)