I started the course on the 7th of January of 2020. I've done PSet0 and PSet1 with no problem. Now I'm in the middle of PSet2. I've done Caesar and submitted it. It appears in my Gradebook. Now I've realized that in my PSet2 there are the following exercises:

  • Caesar
  • Vigenère
  • Crack

But my Gradebook asks for the following one's:

  • Readability
  • Caesar
  • Substitution

For what I see, my materials are the one's of the fall's 2019 course. But my Gradebook corresponds to the 2020 version.

What should I do in order to be able to finish the course and obtain a certificate?

1 Answer 1


As we are in 2020 now, submissions count only if you submit them for CS50x 2020.

There's no way around doing readability, as it's required and has no alternative. It's not that hard, though one might have fun with integer division vs. floating point division.

You can probably submit your old caesar solution using the new CS50x 2020 slug, substitution is an alternative to caesar, so you could skip that one then.

  • The problem is that I don't have the materials to do the problems readability and the others because they don't appear in the 2019 materials. I've been submitting them in CS50x 2020 and CS50x 2019 so far. But now I can't go any further...
    – MDAGLL
    Jan 10, 2020 at 11:26
  • Incredibly! I've logged in again and now they have done the transition from 2019 to 2020. Now I have all the materials for finishing the course! Many thanks Blauelf to answer me!
    – MDAGLL
    Jan 10, 2020 at 11:31
  • If you're doing the course on edX, you have material from years 2020, 2019, 2018 on the main page. edX would expand only the year it thinks you used last, if that's in 2019, it's easy to miss the collapsed 2020 above.
    – Blauelf
    Jan 10, 2020 at 11:35

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