Также называются union find или система непересекающихся множеств.

A disjoint-set data structure maintains a collection $S = \{S_1, S_2, ..., S_k\}$ of disjoint dynamic sets. To identify each set, choose a representative, which is some member of the set. In some applications, it doesn’t matter which member is used as the representative; other applications may require a rule for choosing the representative, such as choosing the smallest member in the set.

Introduction to Algorithms (Fourth Edition) - Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, Clifford Stein (2022)