Problem Set 1

For this problem set, you’ll use CS50 Lab, a cloud-based programming environment with interactive instructions built atop CS50 Sandbox.

What to Do

1.Reply to this thread to say hello (and, if you’d like, a little about yourself!) to other students and staff. If you don’t yet have an account, you should first sign up for Ed.

  1. Submit Hello
  2. Submit one of:
  3. Submit one of:
    • Cash if feeling less comfortable
    • Credit if feeling more comfortable
  4. Submit this form!

If you submit both Marios, we’ll record the higher of your two scores. If you submit both of Cash and Credit, we’ll record the higher of your two scores.

When to Do It

By 11:59pm on Sun 9/15.

How to Get Help

  1. Ask questions on Ed!
  2. Sign up for a tutorial!
  3. Attend office hours!
  4. Email!


  • Try out any of David’s programs from class via Week 1’s sandboxes.
  • 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 hello

    is yielding errors, try running

    help50 make hello