摘要： For a student taking the online course "Data Structures" on China University MOOC (http://www.icourse163.org/), to be qualified for a certificate, he/ 阅读全文

摘要： Consider a positive integer N written in standard notation with k+1 digits a​i​​ as a​k​​⋯a​1​​a​0​​ with 0≤a​i​​<10 for all i and a​k​​>0. Then N is  阅读全文

摘要： 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. Now given a graph with 阅读全文

摘要： Given a singly linked list, you are supposed to rearrange its elements so that all the negative values appear before all of the non-negatives, and all 阅读全文

摘要： Cutting an integer means to cut a K digits lone integer Z into two integers of (K/2) digits long integers A and B. For example, after cutting Z = 1673 阅读全文

摘要： Given a syntax tree (binary), you are supposed to output the corresponding infix expression, with parentheses reflecting the precedences of the operat 阅读全文

摘要： A clique is a subset of vertices of an undirected graph such that every two distinct vertices in the clique are adjacent. A maximal clique is a clique 阅读全文

摘要： After each PAT, the PAT Center will announce the ranking of institutions based on their students' performances. Now you are asked to generate the rank 阅读全文

摘要： Look-and-say sequence is a sequence of integers as the following: D, D1, D111, D113, D11231, D112213111, ... where D is in [0, 9] except 1. The (n+1)s 阅读全文

摘要： The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. A binary search tree (BST) i 阅读全文