摘要：Three Friends Three friends are going to meet each other. Initially, the first friend stays at the position x=a, the second friend stays at the positi 阅读全文

摘要：来源：http://codeforces.com/problemset/problem/1265/B B. Beautiful Numbers You are given a permutation p=[p1,p2,…,pn]p=[p1,p2,…,pn] of integers from 11 t 阅读全文