A — ok.

B — easy.

C — most interesting

D — O(N^2) — precision issue, AC with biginteger / Slower solution — TL issue

E — I don't like this

G — straightforward voronoi

I — input format..

FGHI — TL issue (especially I)

J — see model solution. really?

K — easy.

ICPC WF should keep the level of the problem high. But for this year it seems like a big fail...

Too many problems have issues not related to the core solution.