Интересный раунд, хорошие задачи, спасибо! Не зря вставал в 4 утра)

Problem D was very interesting. Can't solve it during contest but spend all of my time on this problem. I can't understand the editoroal properly for this problem. Can anyone exolain this or give some info on how to become good at this kinds of problems.

During Contest I try to solve this using Binary Search and Two Pointer. But I can't figure it out.

Thanks for contest! Waiting for the next contest!(^_^)7

Easi tasks)0))0)

Unusual terrible bugs at unusual contest time...

Can someone please give proof of why the last segment of days with non-negative temperature has to be processed separately ? and not inserted in the heap. As far as i can think of that the other segments give us 2 changes per segment and the last will only give 1 change. But how is the length of days not the priority when we are considering last segment of non-negative temperature.??

One of my classmates provided a solution for F in . Let us suppose that the ans is less than 16^2 * k. We devide the ans into 2 parts length of which is k. For the hinder part,suppose that if we have known how many letters we can use at most i times in the hinder part,we can get dp[s] interesting numbers while s is the state about it. Of course if i > k we can consider i = k.So the number of kinds of s is 16^k + 1 at most. We can pretreat the dp array in O(16^k + 1). Then we enumerate the front part in O(16^k) and query the instereting number by dp array in O(1). So the solution is . Yeah,my English is really bad.QwQ

Can anyone help me the Problem C. I have wrong answer in test 9. Then I fix some in that, then it accept, but I can't regconize the difference between the old and new. Please help me.

Here the accepted code : http://ideone.com/wPPQrN

Here the "same" code wrong answer test 9 : http://ideone.com/z12T9u

sir, i am struggling with today C, Server here is my code https://paste.ubuntu.com/23652768/ here i upadate my FREE[] while checking each server and getting WA. But some people got AC since they update it at the end,(comment in my code) my question is why this happening?? thanks in advance

sir, i am struggling with today C, Server here is my code https://paste.ubuntu.com/23652768/ here i upadate my FREE[] while checking each server and getting WA. But some people got AC since they update it at the end,(comment in my code) my question is why this happening?? thanks in advance

Can someone explain F in more detail . Is it similar to digit DP ?

Sir, please help me with 747E - Comments. My approach is similar to the editorial : Firstly, I separate all the number and string and store it in a vector. After that, I find the depth of each word by DFS and print it. I think it will work in O(n), but as you see, it nearly TLE in test 9 and TLE in test 29.

Here is my code: 23167334

Thank you very much.

Can someone, please, explain problem F in more details?

Thanks for the help!

I guess I'm misunderstanding problem F statement, because I coded a simple brute force to check the correctness of the second example and the result seems wrong.

Input: 1000000 2

Output: fca2c

My function:

ll count() {
  ll ans = 0;
  char buf[10];
  rp(i,1,0xfca2c) { // my rp macro is inclusive for both ends
    int cnt[16] = {};
    sprintf(buf,"%x",i);
    bool add = true;
    rp(j,0,strlen(buf)-1) {
      cnt[fromhex(buf[j])]++;
      if (cnt[fromhex(buf[j])] > t) {
        add = false;
        break;
      }
    }
    if (add) ans++;
  }
  return ans;
}

It returns 931720, which is less than 1000000.

I'd be thankful if someone could explain me the problem statement.

UPD: Nevermind, my fromhex function had a bug...

For D, i think it is not necessary to use set to do that

first of all, we ignore the first consecutive and the last consecutive segments.

then we gain all the segments which are only consist of non-negative numbers

we sort the segments by their length (the same as the solution)

so we just keep picking from smaller one to large one

finally, for the first consecutive part, it doesn't impact the answer, so we ignore it.

for the last consecutive part, if it is consist of non-negative number, we should ensure whether we can use the left k tires to pass it, if we can, the answer should minus 1.

if it is consist of negative number, we should let answer minus 1 (because u don't need to change at the end of the sequence)

for more infor, here is my code : http://codeforces.me/contest/747/submission/23391692

Hey, can anyone tell how to solve D using DP? It has a DP tag, and I am practicing DP questions, so I would be more than grateful to know about that! :D

This is not linked with problems, can you please look into it fcspartakm