Qualified's blog

During a contest, do you guys stress test your solution if you get WA? If so, what is your script?
By Qualified, history, 5 years ago, In English

By script, I mean what method do you use to stress test your solution(code maybe?)

  • Vote: I like it
  • +3
  • Vote: I do not like it

»
5 years ago, # |
← Rev. 2   Vote: I like it +13 Vote: I do not like it

i verify it on paper firstly even then if i get WA i try to think of corner cases most of the times it works

→ Reply
»
5 years ago, # |
  Vote: I like it +13 Vote: I do not like it

I do this only when the following is true (quite frankly, this happens often):

  • problem is about an array without special properties (that is, random array will be a valid input)

  • I came up with greedy algorithm or dp without a solid proof, and it gives WA

  • I can write a checker, i.e. check that my answer is correct -- for example if I have to output a number of transformations that will lead to something that is easy to check

Then I just replace each "read" statement with something like rand() % max_value_for_this_variable, and run all this in a loop of 1000 and see if there is a mistake somewhere.

Sometimes I also do this if I know I have an integer overflow or out-of-bounds access, but cannot find where.

→ Reply