A......................................................................................... 题目链接→Codeforces Problem 712A Memory and Crow [题意]有n个数b1, b2, ..., bn a1, a2, ..., an是通过等式ai = bi - bi + 1 + bi + 2 - bi + 3....(±)bn得到的 现给你a1, a2, ..., an这n个数,…