摘要：1106 Lowest Price in Supply Chain （25 分） A supply chain is a network of retailers（零售商）, distributors（经销商）, and suppliers（供应商）-- everyone involved in m 阅读全文

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：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

摘要：1084 Broken Keyboard （20 分） On a broken keyboard, some of the keys are worn out. So when you type some sentences, the characters corresponding to thos 阅读全文

摘要：1086 Tree Traversals Again （25 分） An inorder binary tree traversal can be implemented in a non-recursive way with a stack. For example, suppose that w 阅读全文

摘要：pat甲级，树的邻接表存储，dfs，优先级队列 阅读全文

摘要：pat甲级，二叉搜索树的建立，dfs求每层结点树 阅读全文

摘要：pat甲级，出栈顺序是否合理，通过简单模拟方法进行判断。 阅读全文

摘要：1064 Complete Binary Search Tree （30 分） A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties: The lef 阅读全文

摘要：1083 List Grades （25 分） Given a list of N student records with name, ID and grade. You are supposed to sort the records with respect to the grade in n 阅读全文

摘要：1054 The Dominant Color （20 分） Behind the scenes in the computer's memory, color is always talked about as a series of 24 bits of information for each 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 yo 阅读全文

摘要：1094 The Largest Generation （25 分） A family hierarchy is usually presented by a pedigree tree where all the nodes on the same level belong to the same 阅读全文