摘要:
Problem Description Hzz loves aeroplane chess very much. The chess map contains N+1 grids labeled from 0 to N. Hzz starts at grid 0. For each step he 阅读全文
摘要:
A string is finite sequence of characters over a non empty finite set Σ. In this problem, Σ is the set of lowercase letters. Substring, also called fa 阅读全文