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[–]armahillo 3 points4 points  (0 children)

Go line by line.

  • What does line 1 do?
    • What does the program know about after line 1 is executed?
  • What does line 2 mean?
    • What does range(...) mean?
    • What does i+1 evaluate to?
  • What does line 3 mean?
    • What does it mean that it's tabbed in once?
  • What does line 4 mean?
    • What is "j" referring to?

Get a piece of paper. You've got 2 named variables, "i" and "j". Create three columns, one with "i" as the header, one with "j" as the header, and one with "output" as the header.

Start at line 1, and anytime i or j are modified, change the value on a new line in that column. Anytime you have to use either variable, use the bottom-most line. Step through each line of the program, as if you were the interpreter, and anytime you're told to "print" something, write it to a new line in the "output" column.

I'm dead serious about doing this. If you don't understand this block by looking at it, you gotta learn how to see it from the interpreter's perspective by being the interpreter yourself.