Question

Write a C program to run on ocelot which will either set or clear a single bit in a number entered by the user using the binary representation of the number. The user should input the original integer value between 1 and 1000 inclusive using a scanf. Use an unsigned integer type. Output is to the screen. You must use only bitwise operators for this program. You can shift bits and or use the logical bitwise operators.

For this assignment give the user directions asking them to enter the integer and then ask the user if he or she wants to clear or set a bit. Then ask the user which bit to set or clear. That can be a number between 0 and 31. Prompt the user for what should be entered each time. Be sure to validate all user input so the program cannot be crashed. After completing the operation ask the user if they want to do the entire operation again. The user would enter Y or y to do it again. This would be the entire operation from entering the first integer.

You do not need to use getopt for this program since there are no command line arguments.

• If the user enters a 1 as the initial value and a 0 for the bit to clear the result would be 0.

• If the user enters a 1 as the initial value and a 0 for the bit to set the result would be 1.

• If the user enters a 10 as the initial value and a 1 for the bit to clear then the result would be 8.

• If the user enters a 10 as the initial value and a 1 for the bit to set then the result would be 10.

• If the user enters a 10 as the initial value and a 2 for the bit to clear then the result would be 10.

• If the user enters a 10 as the initial value and a 2 for the bit to set then the result would be 14.

  Output for each operation should be easy to read giving the number before the switch and then the decimal number after the switch. No other output should be included.

  The program should compile to create an executable called bitops.

• Test the program with the following commands: o bitops

  ▪ enter 10 as the initial value and a 2 for the bit to clear o bitops

  ▪ enter 10 as the initial value and a 1 for the bit to set

Answer 1

Code to copy:

#include <stdio.h>

int main()

{
//declare the variables
int num, bit, res;
int option;
char ch = 'Y';
//iterate a do-while loop
do
{
/*Read an integer value between 1 and 1000
Validate the num. Iterate the loop until user enter
correct num.
*/
do
{
printf("Please enter an integer between 1 and 1000: ");
scanf("%d", & num);
if (num < 1 || num > 1000)
{
printf("Invalid Input.\n");
}
} while (num < 1 || num > 1000);
/*prompt and read the num if user wants to clear or set a bit
Validate the num. Iterate the loop until user enter
correct num.
*/
do
{
printf("\nDo you want to set or clear?\n1. Set\n2. Clear\nEnter your option: ");
scanf("%d", & option);
if (option < 1 || option > 2)
{
printf("Invalid Invalid.\n");
}
} while (option < 1 || option > 2);
//if the user wants to set the bit.
if (option == 1)
{
/*prompt and read the bit number to set
Validate the num. Iterate the loop until user enter
correct num.
*/
do
{
printf("\nEnter the bit to set (0-31): ");
scanf("%d", & bit);
if (bit < 0 || bit > 31)
{
printf("Invalid Invalid.\n");
}
} while (bit < 0 || bit > 31);
//using logical bitwise operators
//set the bit of the num number.
//Left shift 1 to bit number of times and perform bitwise OR (|)with num
res = (1 << bit) | num;
printf("The decimal number before setting %d bit: %d\n", bit, num);
printf("The decimal number after setting %d bit: %d\n", bit, res);
}
//if the user wants to clear the bit.
if (option == 2)
{
/*prompt and read the bit number to set
Validate the num. Iterate the loop until user enter
correct num.
*/
do
{
printf("\nEnter the bit to clear (0-31): ");
scanf("%d", & bit);
if (bit < 0 || bit > 31)
{
printf("Invalid Input.\n");
}
} while (bit < 0 || bit > 31);
//using logical bitwise operators
//clear the bit of the num number.
//Left shift 1 to bit number of times, apply the compliment (~),
//and perform bitwise AND (&) with num.
res = num & (~(1 << bit));
printf("The decimal number before clearing %d bit: %d\n", bit, num);
printf("The decimal number after clearing %d bit: %d\n", bit, res);
}
//ask the user to repeat this process again
printf("\nIf you want to repeat, press Y otherwise N: ");
scanf(" %c", & ch);
printf("\n");
} while (ch == 'Y' || ch == 'y');
return 0;

}

Code Screenshot:

Output Screenshot: