https://codeforces.com/contest/1188/problem/B\begin{align} & (x+y)(x^2+y^2)=k \\ \iff & x^3 + x^2 y + x y^2 + y^3 = k \\ \iff & \frac{x^4-y^4}{x-y}=k \\ \iff & x^4 - kx=y^4 - ky \end{align} My first approach is to solving cubic equation. I…

https://codeforces.com/contest/1188/problem/CSuppose that the array is already sorted. Let f(x) be the number of subarrays such that any difference between adjacent elements is greater than or equal to x. We then have the answer as f(1)+f(…