Classwork 23

Logistics

Due: Monday, May 1st AoE.
Submission instructions: make sure that the required file (flags.c) is in your /classwork/week15/mon/ directory.
Deadline reminder: after the deadline passes, you cannot earn any points for this assignment.

Learning outcomes

Practice using bitwise operators

Assignment

If on campus and connected to a MSU network:

Log in to the server.
From your home directory, navigate to classwork/week15/mon/, creating directories week15 and mon if necessary.
Copy the flags.c file from /public/classwork/week15/mon and fill in the two TODOs. Don’t change the if statements or print statements.

If off campus:

Copy the code below. Using a C compiler of your choice (if you don’t have one, use https://www.jdoodle.com/c-online-compiler/), fill in the two TODOs. Don’t change the if statements or print statements. Your program should print
```
First flag set
Second flag set
Third flag set
Second flag set
Third flag set
```
In a DM to Lucy on Discord, copy your code. Surround your code with three backticks (`), found under the tilde (~) on your keyboard, on the first line and last line so that Discord doesn’t think asterisks are meant to italicize. Or attach it as a file.

Autograder

You can run the autograder yourself by running

/public/classwork/week15/mon/autograder.sh

The autograder.txt file will be created or replaced. You may get a few lines of output about not being able to remove files, etc. This is okay.

For those who DM their code, if your program has the output

First flag set
Second flag set
Third flag set
Second flag set
Third flag set

you will get full credit.

Code to copy

#include <stdio.h>
#define FIRST_FLAG 0b1
#define SECOND_FLAG 0b10
#define THIRD_FLAG 0b10000

int main() {
	int flags = 0;

	// TODO: set all three flags on using bitwise or (|)

	// don't change these
	if (flags & FIRST_FLAG) {
		printf("First flag set\n");
	}
	if (flags & SECOND_FLAG) {
		printf("Second flag set\n");
	}
	if (flags & THIRD_FLAG) {
		printf("Third flag set\n");
	}

	// TODO: turn FIRST_FLAG off using bitwise and (&) and bitwise not (~)

	// don't change these
	if (flags & FIRST_FLAG) {
		printf("First flag set\n");
	}
	if (flags & SECOND_FLAG) {
		printf("Second flag set\n");
	}
	if (flags & THIRD_FLAG) {
		printf("Third flag set\n");
	}
}