Recitation 05: Debugging and Linear Search

• Handout [Solution] find.c0 lin_search.c0 lin_isqrt.c0

Debugging

Before we get to debugging, remember that a little extra work up front can save you a lot of time and frustration in the long run. Test and debug incrementally. So, after you write a function, test it to make sure everything works as expected. It'll be a lot easier to find that bug in foo() than later when the bug happens once bar() calls foo().

For these examples, some notes can be found in a comment at the top of the file.

• debugging1.c0 [sol]
• debugging2.c0
• debugging3.c0
• debugging4.c0

Linear Search

• See code linked above.
• Pay attention to the is_in() function, since we'll be using it in our annotations.
• As an activity to better understand how contracts work together, it may be worth while to connect the contracts together. For example, which loop invariant supports which postcondition? They usually have a very similar function and are easy to identify.
• Variants:
  • What if we want to find the index of the last occurance of the element instad of the first occurance? Change the code accordingly. [code]

If you have any comments or see any errors, please let me know.