摘要：
You are given three positive integers N,x,y.Please calculate how many permutations of 1∼N satisfies the following conditions (We denote the i-th numbe 阅读全文
摘要：
You are given two integers N,CN,C and two integer sequences aa and bb of length NN. The sequences are indexed from 11 to NN. Please solve the followin 阅读全文