OJ Board

Petya wants to organize programming contest in his institute and he has to pass some consecutive bureaucratic procedures.
At each step Petya get or pay some money.

He may pay 100 coins to skip next bureaucratic procedures or 200 coins to skip next two procedures or k*100 coins to skip next k ...

I did it with O(n^2) ... but it's too slow... i can't understand how to do it in O(nlogn)

but this can be done by binary search and time will be O(n log n)
I will now try this...

I think i can't do this because time will be O(n^2) but I need faster

Hm.. I know how to draw them.. but I need equations of tangents

Can you help me with DP solution?

D[k] - is best solution for first K intervals

If I know D[1] ... D[k - 1]
How to express D[k] ?

Help
How to find common tangent to two circles?

Hi all !

Can somebody tell me how to solve this problem?

There are N intervals (ai, bi). ai and bi are integers not exceeding 2'000'000'000 by their absolute value.
Your task is to find the number of ways we could choose a maximal subset of disjoint intervals.
1 ≤ N ≤ 100000

How to solve this problem ?
Given a1, b1, c1
0<= a1, b1, c1 < 2^24

How to find such a, b, c that

a1 = (b * c) xor a
b1 = (a * c) xor b
c1 = (a * b) xor c

all operations are done mod 2^24

Thanks, I'll try to solve them

please tell me some uva problems with max flow or max matching application to train my skill

..