摘要：
" 题目链接 " Problem Description There are n nonnegative integers a1…n which are less than p. HazelFan wants to know how many pairs i,j(1≤i0的这些对数减掉。 这样求出来 阅读全文
摘要：
" 题目链接 " Problem Description HazelFan wants to build a rooted tree. The tree has n nodes labeled 0 to n−1, and the father of the node labeled i is the 阅读全文
摘要：
" 题目链接 " Problem Description There is a nonnegative integer sequence a1...n of length n. HazelFan wants to do a type of transformation called prefix X 阅读全文
摘要：
" 题目链接 " Problem Description There are n points on the plane, and the ith points has a value vali, and its coordinate is (xi,yi). It is guaranteed tha 阅读全文