摘要：
##1108 Finding Average (20 分) The basic task is simple: given N real numbers, you are supposed to calculate their average. But what makes it complicat 阅读全文
摘要：
##1107 Social Clusters (30 分) When register on a social network, you are always asked to specify your hobbies in order to find some potential friends 阅读全文
摘要：
##1105 Spiral Matrix (25 分) This time your job is to fill a sequence of N positive integers into a spiral matrix in non-increasing order. A spiral mat 阅读全文
摘要：
##1102 Invert a Binary Tree (25 分) The following is from Max Howell @twitter: Google: 90% of our engineers use the software you wrote (Homebrew), but 阅读全文
摘要：
##1167 Cartesian Tree (30 分) A Cartesian tree is a binary tree constructed from a sequence of distinct numbers. The tree is heap-ordered, and an inord 阅读全文