Problem A: Coder(384A)
Problem B: Multitasking(384B)
Problem C: Milking cows(383A)
Problem D: Volcanoes(383B)
Problem E: Propagating tree(383C)
CodeForces Round #225 (Div. 2)
原文：http://blog.csdn.net/keshuai19940722/article/details/18967741
