These three problems are almost the same.
CF618F [Double Knapsack]: https://codeforces.me/problemset/problem/618/F
CF1836E [Twin Cluster]: https://codeforces.me/contest/1836/problem/E
Beijing College Entrance Exam:
Given two positive integer arrays $$$A$$$ and $$$B$$$, such that:
$$$len(A) = len(B) = n$$$
and
$$$\forall 1 \leq i \leq n$$$, $$$1 \leq a_i, b_i \leq n$$$.
Prove there are subsegments $$$[x, y] \subseteq [1, n]$$$, $$$[z, w] \subseteq [1, n]$$$ such that $$$\sum\limits_{i=x}^y A[i] = \sum\limits_{j=z}^w B[j]$$$. For example, $$$n=4, A=[1,2,3,4], B=[4,4,4,4]$$$, then $$$x=4, y=4, z=1, w=1$$$ is a solution.
I think twin cluster is pretty different, unless you consider every problem that considers pigeon hole principle the same (it is all same mindset but setup and realization is different).
But twin cluster is also prefix sum + pigeon hole?
So is half other pigeonhole problems.
I agree that Twin Cluster should not be grouped with the others. Anyway, see Putnam 1993 A4 as well.