ID NAME QUALITY USERS ACC % DIFFICULTY C I
28451 Ada and Cities   9 104
19
17
28450 Ada and Path   7 80
15
28
17261 Bank robbery   2 235
17
23
10145 Birthday Cake   7 233
12
12
1693 Coconuts   12 663
21
28
3579 Disjoint Paths   4 307
24
27
4110 Fast Maximum Flow   40 2323
26
21
373 Greedy island   4 472
27
24
962 Intergalactic Map   3 538
19
28
4206 Fast Maximum Matching   27 1722
24
20
4485 MobiZone vs VinaGone   7 297
17
31
4227 "Shortest" pair of paths   3 185
23
17
3868 Total Flow   12 1300
14
12
287 Smart Network Administrator   3 410
24
31
203 Potholers   22 2048
16
12
22379 Mobile Company 2   2 65
13
17
4457 Shopping II   3 132
17
1
377 Taxi   14 1198
13
16

#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