Objectives:

Number Systems

Bitwise Operations

Masking

Program:

Write a C program to extract information hidden in a whole number. The information pertains to users participation in a contest and winning some prizes. The information hidden in the input number are as follows:

The number of participants are: The lowest 5 bits in the input number.

The number of prizes one can win are: Bits 2, 3, 4 from the right.

The chance of winning in this competition is stored in the 5^th bit from right.

1 indicates high chance and 0 indicates low chance.

Function Prototype:

Write function prototypes at the beginning of the program before main().

Write the function definitions (the code) after main().

Required Function: Every function must be preceded with 4 lines of comments describing its name, input(s), output type, and task.

1) get_code ( ) function

Input parameter: None

- Output: int

-Task: prompt the user to enter a whole number in range of -100 and 100, both inclusive. Return the number as output.

Validation: Use a loop to validate the range of the input number.

2) display_binary ( ) function

- Input parameter: int

- Output: void

-Task: Display the input number in 16 bit binary.

Display a space between every 4 bits for clarity.

main( )

Declare an int variable named lottery. Declare other int variables to store the number of participants, number of prizes and etc.

Invoke the function get_code() and store its output in variable lottery.

Display the lottery in hexadecimal (use %X in printf ).

Define a mask to retrieve the number of participants. Tip: 0001 1111

Use this mask and bitwise & to retrieve the number of participants.

Display the number to the screen.

Define a mask to retrieve the number of prizes. Tip: 0000 1110.

Perform a bitwise & between the lottery and the mask, shift the result to the right one bit to get the number of prizes - Display the outcome to the screen.

Define a mask to retrieve the chance of winning in the contest. Tip: 0001 0000

Use the bitwise & between the mask and the lottery, to get the value of the 5^th bit. Display the chance of winning to the screen.

Invoke the function display_binary ( ) to display lottery in binary.

Flip the 7^th and 8^th bits from the right in the number (that is change bit 1 to 0 and bit 0 to 1). Define a mask 1100 0000 and do a bitwise ------- between the mask and the number to flip those bits.

Invoke the function display_binary() to display the updated number to the screen in binary see if those bits are flipped..

Rerun the program. Add rerun loop to allow the user try other codes.