I want to know what are the 0's and 1's in the cs50 gradebook? Are they scores or some return values? Because I have got 0 for 'hello world.c' and also for various input values of 'greedy.c' even when the output is absolutely correct. E.g. in greedy.c if the input is 0.41, the output should be 4 = 0.41 dollars = 41 cents = 1 quarter + 1 dime + 1 nickel + 1 penny. But in my gradebook I have got a zero for that.

  • Sounds like you didn't check your work before submitting? Be sure to use the check50 tool when it is available (as it is for greedy). That will tell you where your errors are.
    – curiouskiwi
    Commented Jul 22, 2014 at 7:19
  • after listening to your advice i used check50 tool and it is showing the following errors: input of 0.41 yields output of 4 input of 0.01 yields output of 1 as per as my knowledge goes .41 should return 4 25+10+5+1, and 0.01 should return 1.but i have got zeros for these inputs Commented Jul 23, 2014 at 12:28
  • i have even got a 0 in hello world! Commented Jul 23, 2014 at 12:34
  • Please edit your original question and paste in the sandbox URL that check50 gives you. That way, we can see the errors you are getting and help better.
    – curiouskiwi
    Commented Jul 23, 2014 at 19:36

1 Answer 1


Grades are based on a scale of 0 to 1. 0 = 0% and 1 = 100%. 0.67 would be 67%.

If the pset has multiple evaluation criteria for programs using check 50, you can expand the view to see which individual checks your program failed to pass.

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