I was confident I had solved yesterday's C question correctly. But could not clear the idleness verdict even after flushing the output. What can be the reasons my flush didn't work as expected ?? I tried all ways fflush(stdout), cout.flush() and even just endl. None of them could clear pretest 2. All gave me idleness issues.

void response(int x, int y) {
    cout << "! " << x << " " << y << endl;
    cout.flush();
}
 
int query(int x, int y) {
    cout << "? " << x << " " << y << endl;
    cout.flush();
    int res = ini();
    return res;
}

Complete submission : 249149514

I was solving this question 1731C - Even Subarrays

I was getting TLE on test 2 until i decided to have a look a at the editorial Editorial suggested an n root n complexity answer => 186975655

which then i implemented the same in java and 237133047

i felt maybe hash map collisions could lead to this, so i tried with trie data structure as well that didnt even cross test 3

Does it ?

This 22nd of october, We are witnessing something entirely different. 3 contests Div1, Div2, Div3 running parallely.

Even though there are 3 days left for registering, there is quite a chance the Div 2 contest will be given entirely by experts.

I was wondering if this makes it more difficult for positive delta or nothing changes ?

Hello Codeforces Community,

I have recently turned expert in the previous educational round. And now seek advice on how to conquer the next step — Turning Purple

I have solved lots of questions in the 1400 to 1500 range which helped me in consistently solving A B and C in almost every Div 2 contest. Whenever i attempt a 1700 — 1800 problem it seems way too difficult from what i have previously solved.

Are there some advanced algorithms or concepts i need to learn before practicing to conquer the next step ? Or spamming practice is the answer ?