Изменения

* [http://www2.mta.ac.il/~amirben/downloadable/ufd.pdf A. Ben-Amram, S. Yoffe. A Simple And Efficient Union-Find-Delete Algorithm]

* [https://www.cs.princeton.edu/courses/archive/fall05/cos528/handouts/Union-Find%20with%20Constant%20Time%20Deletions.pdf S. Alstrup, I. L. Gørtz, T. Rauhe, M. Thorup, and U. Zwick. Union-find with constant time deletions]