a-linked-list-and-related-processing

使用C语言完成党的霍夫曼编码，主要使用树的数据结构，作为巩固数据结构的练习(Using the C language to complete the party' s Huffman coding, the main use of the tree data structure, data structure as a consolidation exercise)

输入N个点的坐标，判断这N个点能否构成一个凸多边形。(Enter the coordinates of N points, to determine whether the N points form a convex polygon.)

1.建立两个有序得链表（带表头，用头插法）； //2.写一算法在单链表上实现线性表的ListLength(L)运算。 写一算法将单链表中值重复的结点删除，使所得的结果表中各结点值均不相同。 (1. The establishment of two ordered lists too (with header, with the first interpolation) // 2. To write a method to achieve a single linked linear form of ListLength (L) operations. Write an algorithm to list the value of a single node to delete the duplicate, so the results in the table are not the same as the value of each node.)

自己用c语言写的一个模块化多电平最近电平调制排序的c程序，希望对大家有帮助(Own use c language written in a modular multi-level modulation level recently sort of c program, we hope to help)

设有一头指针为L的带有表头结点的非循环双向链表，其每个结点中除有prev（前驱指针），data（数据）和next（后继指针）域外，还有一个访问频度域freq。在链表被起用前，其值均初始化为零。每当在链表中进行一次Locate(L,x)运算时，令元素值为x的结点中freq域的值增1，并使此链表中结点保持按访问频度非增（递减）的顺序排列，同时最近访问的结点排在频度相同的结点的最后，以便使频繁访问的结点总是靠近表头。试编写符合上述要求的Locate(L,x)运算的算法，该运算为函数过程，返回找到结点的地址，类型为指针型。(Has a head pointer is non-circular doubly linked list L with a header node, each node in addition to prev (precursor pointer), data (data) and next (successor pointers) outside, there is an access frequency degree domain freq. Before the list was hired, their values are initialized to zero. Whenever carried out in the list once Locate (L, x) when the operation, so that the element node x is the value in freq domain by one, and keep this list in the node-access frequency of non-increasing (decreasing) the order, while a recent visit to the nodes in the same row of the frequency of the last node, so that the nodes are frequently accessed tables are always near the head. Locate (L, x) algorithm is prepared in accordance with the above requirements of the test operation, the operation as a function of the process, return to find the address of the node of type pointer.)

一．问题描述 对2006年度全国80多个城市的每天空气质量状况进行查询、排序等操作。 空气质量状况对象包括城市代码、城市名称、首要污染物、污染指数、污染物级别、空气状况、年、月、日 二、实验要求 1． 普通查询：输入城市名称和城市代码，分别查询该城市每天、每周、每月、每季度和全年的空气质量状况 例子：查询太原市2006年第8周的空气质量状况 2．统计查询： （1）输入城市名称和城市代码，分别查询该城市每周、每月、每季度和全年的空气质量为优、良、轻微污染、轻度污染、重污染的天数 例子：查询石家庄市2006年第2季度空气质量为轻微污染的总天数 （2）根据时间查询空气质量状况：输入周编号、月编号、季度编号或年编号，以及空气质量为优、良、轻微污染、轻度污染、重污染的天数，查找相应的城市名称 例子：查询2006年5月，空气被轻度污染3天以上的城市有哪些？ 3．排序查询 （1）输入周编号、月编号、季度编号或年编号，查询城市空气质量的排行榜 例子：查询2006年第6周，全国空气平均质量最好的前20个城市为哪些？ 三、数据文件 Data.txt(one. Problem Description of the air quality day in 2006 more than 80 cities nationwide query, sorting and other operations. Air Quality objects include city code, city name, the primary pollutant, pollution index, contaminant level, air condition, year, month, day two, experimental requirements 1. General Queries: Enter a city name and city codes, each query in the city daily, weekly, monthly, quarterly example air quality and full year: Queries air quality in Taiyuan first eight weeks of 2006 2. Statistical inquiry: (1) enter a city name and city codes, each query in the city weekly, monthly, quarterly and annual air quality as excellent, good, slight pollution, light pollution, heavy pollution days example: inquiry Shijiazhuang City in 2006 second quarter, the air quality is the total number of days a slight pollution (2) according to time of the query air quality conditions: enter the week number, month number, quarter number or in number, and the air quality is excellent, good, sli)

最优二叉搜索树问题具有最优子结构性质，即其任意一棵子树都是一棵独立的最优二叉搜索树，所以可以采用动态规划方法，并且在每次更新时保存子树的根。(Optimal binary search tree problem has optimal substructure property that any of its sub-tree are an independent optimal binary search tree, so you can use dynamic programming methods, and save each update subtree roots.)

这是数据结构很重要的程序，主要是课后题的答案，和代码，功能很强大(the data struct of the book)

简单的迷宫问题，有点土，还望大家多指点指点，在此感激不尽。(????? mad spasm, ? Tang Gao, ? oligonucleotide ??? Ning Ning ? ?, Hitomi ?????.)

本系统采用C语言编写，利用邻接链表实现最短路径问题，关键路径问题等(The system uses the C language, using adjacency list realize the shortest path problem, critical path issues)