ID NAME QUALITY USERS ACC % DIFFICULTY C I
28451 Ada and Cities   4 65
12
17
28450 Ada and Path   5 58
17
30
17261 Bank robbery   2 229
17
23
10145 Birthday Cake   8 202
14
12
1693 Coconuts   10 611
21
30
3579 Disjoint Paths   2 290
23
34
4110 Fast Maximum Flow   31 2025
25
21
373 Greedy island   2 426
30
27
962 Intergalactic Map   4 509
22
29
4206 Fast Maximum Matching   17 1513
24
19
4485 MobiZone vs VinaGone   4 252
21
34
4227 "Shortest" pair of paths   3 175
23
17
3868 Total Flow   9 1241
12
13
287 Smart Network Administrator   3 390
24
31
203 Potholers   18 1893
17
14
22379 Mobile Company 2   1 53
12
17
4457 Shopping II   2 124
17
1
377 Taxi   11 1146
13
17

#max-flow

The problem involves maximum flow problem

https://en.wikipedia.org/wiki/Maximum_flow_problem http://www.cs.princeton.edu/courses/archive/spr04/cos226/lectures/maxflow.4up.pdf