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It looks like a straightforward question. I used the formula of Catalan numbers and the C "bignum" routines. But I kept getting TLE. Is there any trick to improve the running time? BTW, which is more costly, bignum multiplication or bignum division?

I use sweepline algorithm to solve this question. It yields right result on sample test data, but got "Invalid Memory Reference" after submitted. Could anybody help me to find out what's wrong or provide me some longer test set? Thanks in advance. :D

#include <iostream>
#include <vector>
#include ...

I still don't understand why F-W algorithm can be used here - to maximize the profit it sounds like a longest path problem.