Summer Contest #3

Because everyone loved the last summer contest, spencercompton made one. He also roped in ksun48.

This round will not be rated.

Before the contest date, you may wish to check out the tips and help pages.

The contest consists of 1 question with a range of difficulty from IOI through IOI. It is highly recommended to read all of the problems. You will have 1 hour to complete the contest. After the contest window begins, you may begin at any time. Your personal timer will start counting down, and you will be able to submit until 1 hour from when you started, or until the hard deadline, whichever comes first.

After joining the contest, you proceed to the Problems tab to begin.

We have listed below some advice as well as contest strategies:

  • Start from the beginning. Ties will be broken by the sum of times used to solve the problems starting from the beginning of the contest. The last submission time of your highest score will be used.
  • Remove all extra debugging code and/or input prompts from your code before submitting. The judge is strict — your output must match the judge output exactly.
  • Do not pause program execution at the end. The judging process is automated. You should use stdin / stdout to perform input / output, respectively.
  • It is guaranteed that all the problems will be solvable with C++.

At the end of the contest, you may comment below to appeal a judging verdict. In the case of appeals, the decision(s) of our staff is final.


Problem Points AC Rate Users
XOR Sum 15 32.3% 45


  • -1
    nimaaa  commented on July 25, 2018, 12:12 p.m.

    Harder than IOI !

  • -4
    echofox  commented on July 21, 2018, 8:23 p.m.

    this is so sad

  • 8
    ADMathNoob  commented on July 18, 2018, 10:13 p.m.

    Wow, "a range of difficulty from IOI through IOI"!? :O

  • -8
    kobortor  commented on July 15, 2018, 11:25 p.m.

    This comment is hidden due to too much negative feedback. Click here to view it.