摘要：
题目地址：http://codeforces.com/contest/1042/problem/D 题意：给你n个数，问有多少个区间的和的值小于t 分析：区间和问题，常常用到前缀和来进行预处理，所以先预处理出前缀和数组sum sum[i]代表前i个数的和，那么sum[i]的贡献就是, 当i<k<=n 阅读全文
摘要：
There is a company that has N employees(numbered from 1 to N),every employee in the company has a immediate boss (except for the leader of whole compa 阅读全文