ID NAME QUALITY USERS ACC % DIFFICULTY C I
14834 Foxlings   32 934
18
12
15267 FRIEND CIRCLE   25 965
13
11
18284 Petya and the Road Repairs   57 817
19
22
2731 Inventing Test Data   3 365
14
27
26193 Lost and survived   43 756
15
12
3932 Point Connection Game in a Circle   3 711
13
21
726 Promotion   23 1933
12
8
1707 Reliable Nets   4 331
28
23
71 Tree   2 413
12
9

#disjoint-set-2

A data structure that keeps track of a set of elements partitioned into a number of disjoint subsets

https://en.wikipedia.org/wiki/Disjoint-set_data_structure https://www.youtube.com/watch?v=gcmjC-OcWpI - video lecture