Took the contest 2 days ago but was pretty busy yesterday (with some discrete math project skull) so doing writeup rn in school lmao

0:00 - 0:02

Read through problems. p4 trivial w/ a bunch of casework. p5 maybe possible to bruteforce small cases, p6 kinda impossible

0:02 - 0:51

The general idea for p4 was essentially just to determine the shift in initial gondolas, then notice that replacement (adding gondola i) can occur in any slot whose final gondola is at most number i.

I did by subtasks - set 1 at 25 min, set 2 at 35 min, AC at 51 min.

0:51 - 1:14

Thought a bit more on p5 and p6. Small case on p5 trivial by build whole graph, individual protocol cases handled by separate cases. (prot. 0 must form tree, dp trivial, prot. 1 always forms disconnected graph, prot. 2 always makes complete connected component, also trivial.)

p6 subtask 1 was obviously solveable with literally any algo, went for the low-hanging fruit 2^n. Couldn't think of subquadratic, did see quadratic but for some reason didn't see that subtask 2 was possible with it. idk

1:14 - 1:55

Wrote up individual cases for p5, passed subtasks 2-4 by 1:39. Then got small case at 1:55 for 46 pts.

1:55 - 2:15

Wrote up small case 2^n on p6, 7 pts.

2:22

Directly out of contest log: "i claim that i am screwed on p3"

2:32

Also from contest log: "i tentatively claim that i am also screwed on p2"

So, that ended IOI 2014. With 325 points total, this got me over the silver line.. (323 points)

tags: programming ioi contest-logs