An old blog discussed about how to ac every problem. One comment from a certain user struck me. Instead of the usual ~10^{-6736}~ chance, I can make it ~100\%~ under some conditions.
Conditions
These following conditions must be met in order to guess, no, actually get the tests:
- Being allowed to submit as many times as you want.
- No batch grading.
- Ability to use binary search.
- Patience.
Proccess
There is one trick I would like to introduce to you: the Kim Jong Un trick.
Code:
void nuke(){
while (1){}
}
How does this work?
When you call the ~nuke()~ function, your code automatically gets TLE (Time Limit Exceeded).
So how do we use this to our advantage?
For instance, the input is only a positive integer ~n~ ~(1 \le n \le 1000)~. What you are going to do is binary search on ~n~. First, you set the left bound ~l~ to 1, and the right bound ~r~ to ~1000~. You set ~mid~ to ~(l + r)/2~. You read ~n~ from the input, check:
- If ~n < mid~, call the ~nuke()~ function.
- Else, don't call the function.
After that, submit your code and check if it gets TLE. If it does, it means that ~n < mid~, and you should set the right bound to ~mid - 1~, if it doesn't, you set the left bound to ~mid + 1~. After about ~10~ submissions, you will be able to guess n of ~1~ test.
Do note that it's manual binary search (you do it by hand), not regular binary search.
This also works with bigger input (~2+~ integers, a whole array, etc.). For instance, you are trying to guess tests of a problem in which input consists of an array. You guess ~n~ using the method above, and guess ~a_i~ for all ~1 \le i \le n~ using the same mentioned method. Though if the array is long (~10^6+~ elements), good luck with staying up all night to submit your code tens of millions of times.
Bình luận
instead of doing things in base 2 you can do it in base 256 using the exit code. also you can hash the input and if its slightly above tl you can output the output in the "Output" box...
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