Mr Zhang

摘要： 1124 Raffle for Weibo Followers （20 分） John got a full mark on PAT. He was so happy that he decided to hold a raffle（抽奖） for his followers on Weibo -- 阅读全文

摘要： 1134 Vertex Cover （25 分） A vertex cover of a graph is a set of vertices such that each edge of the graph is incident to at least one vertex of the set 阅读全文

摘要： 1142 Maximal Clique （25 分） A clique is a subset of vertices of an undirected graph such that every two distinct vertices in the clique are adjacent. A 阅读全文

摘要： 1146 Topological Order （25 分） This is a problem given in the Graduate Entrance Exam in 2018: Which of the following is NOT a topological order obtaine 阅读全文

摘要： 1138 Postorder Traversal （25 分） Suppose that all the keys in a binary tree are distinct positive integers. Given the preorder and inorder traversal se 阅读全文

摘要： pat甲级，二叉树遍历 阅读全文

摘要： 1050 String Subtraction （20 分） Given two strings S​1​​ and S​2​​, S=S​1​​−S​2​​ is defined to be the remaining string after taking all the characters 阅读全文

摘要： 1140 Look-and-say Sequence （20 分） Look-and-say sequence is a sequence of integers as the following: D, D1, D111, D113, D11231, D112213111, ... where D 阅读全文

摘要： 1125 Chain the Ropes （25 分） Given some segments of rope, you are supposed to chain them into one rope. Each time you may only fold two segments into l 阅读全文

摘要： pat甲级，散列 阅读全文