North America-greater NY 2013__acm_ Game

Reprint please indicate the source, thank http://blog.csdn.net/ACM_cxlove?viewmode=contents by---Cxlove

A: Directly enumerate the island's two endpoints, both sides should be low, the middle part can not lower than the two ends.

B: Directly calculate the meeting time of two bicycles.

C: According to the topological order of violence.

D: Direct Violence for circulation section

E: The principle of tolerance, enumeration before I have how many are right, the rest of the arbitrary.

F:dp,dp[i][j][k] represents the case of three rows.

G: For a point with a degree of 1, the other two endpoints of the triangle are definitely at the end of the first non 0 on both sides of the vertex.

H: Play the table to find the law, found the answer is P ^ {i-j} */binom {i}{j}

I: Try for the fruit ... It's a hole left in the geometry. Probably there is a triangle, find a point, make/sum_{i = 0}^{2} {(0.2 + e[i]) * Dist[i] ^ 2} minimum.

Tried a simulated annealing, failed.

To push the formula, first find the triangle three edge of the linear equation, and then to the distance, get the formula, and then analyze the maximum value. Theoretically it should be done, but I am lazy and find the formula more complicated ....

code:https://github.com/cxlove/acm_icpc/tree/master/regional/north%20america%20-%20greater%20ny_2013