Does not compute 0*0 correctly.
Please avoid margin comments. They tend to make programs LESS readable, not more readable.
Some results have leading zeros.
Programs that do not compile are not acceptable, and receive no credit.
NEVER turn in a C++ program (or even write one to begin with) that includes a file with an absolute name. Your program will not compile. See item R4. Includes should always use relative file names.
Please avoid long lines. They make your program hard to read and to print. Any line longer than 80 characters is too long.
Indentation is poor. I expect to see a well indented program with consistent indentation rules. Your program might appear poorly indented to me because you have used tabs with nonstandard tab stops. I cannot spend time guessing where you have put tab stops. Use the standard of a tab stop every 8 characters. If you use a different setting, you will probably lose points for having a poorly indented program.
Your sum function does not allow the result array to be the same as the A array. Read the instructions.
You did not include the shared comment that is necessary for the contracts to make any sense. So you have senseless contracts.
You have not put contracts in your program. I expect to see a contract for every function.