Problem Set 4

Collaboration on problem sets is not permitted except to the extent that you may ask classmates and others for help so long as that help does not reduce to another doing your work for you, per the course’s policy on academic honesty.

What to Do

Are you an edX student? Don’t attempt to follow these instructions! Head over to cs50.edx.org or cs50.harvard.edu/x, and use the instructions there instead! These instructions are only for the on-campus course!

Submit one of:
- this version of Filter if feeling less comfortable
- this version of Filter if feeling more comfortable
Submit Recover
Submit this form.

If you submit both versions of Filter, we’ll record the higher of your two scores.

When to Do It

By .

How to Get Help

Browse or search for answers on Ed or post your own questions!
Browse the CS50 Manual Pages for functions that might be useful.
Watch Shorts for any topics that you still have questions about.
Sign up for a tutorial!

Advice

Try out any of David’s programs from Week 4.
If you see any errors when compiling your code with make, focus first on fixing the very first error you see, scrolling up as needed. If unsure what it means, try asking help50 for help. For instance, if trying to compile hello, and
```
make filter
```
is yielding errors, try running
```
help50 make filter
```
instead!