data structure It is an operation object in the programming problem of non numerical calculation , And the relationship between them and the operation of related issues .
The process of computer processing , In fact, it is the process of processing data , The computer solves a specific The steps to the problem [1]：
（1） To analyze problems , Determine the data model .
（2） Design corresponding algorithm .
（3） Programming , Run and debug the program until you get the correct results .
Programming = data structure + Algorithm
（Program = Data Structure + Algorithm）
data structure (Data Structure) Is the organizational structure of data , To organize 、 Store the data .
Algorithm (Algorithm) It's the way or process to solve the problem .
To deal with problems, we need to analyze data , And then get the solution to the problem , First, structure the data .
data ： It refers to the general term of all media that can be input into the computer and processed by the computer program , It's used for input to an electronic computer for processing , Numbers and letters with a certain meaning 、 Symbol and analog quantity, etc . For example, the characters you have in the game 、 equipment 、 Grade 、 Gold coins, etc. , These are all data , And these data are divided into many different types and stored in the computer .
data elements ： It refers to the smallest unit defined by classifying data according to a certain standard , It contains a certain meaning , It can be treated as a whole . Like humans , People are data elements .
Data item ： Is a single member item of a data element , That is to say, a data element is composed of several data items . For example, the data element of human , Can have eyes 、 Ears and other data items , You can also have a name 、 Data items such as age .
Multiple related data items form a data element , Many data elements make up a large amount of data .
Data objects ： When we process and analyze data , Generally, a limited number of data elements with the same nature will be selected from a large amount of data , Make a collection , As an object of study , be called Data objects . Data objects are of the same nature A collection of finite data elements , It is a subset of data . For example, the upper case data object is a set C={'A','B','C',…,'Z'};1～100 The integer data object of is a set N={1,2,…,100}.
data structure ： It refers to the data elements involved and the relationship between them , It can be regarded as a collection of data elements with specific relationships between them .
For example, the ranking of exams , The teacher will make a table in order according to the grades , From first to last , In order . In fact, this is a data structure , It's called a sequence table . The data object is everyone's ranking , Including ranking 、 full name 、 Performance, etc. . Structure is the order of ranking , Everyone has only one front rank and one rear rank （ Except for the first and last place ）.
The data structure is logical structure 、 Storage structure （ Physical structure ） And data operations .
Logical structure refers to the relationship between data elements , It is computer independent . There are usually four types of structures ：
aggregate ： The data elements in the structure belong to the same type , Nothing else .
Linear structure ： There is a one-to-one relationship between the data elements in the structure . Defines the linear relationship .
Tree structure ： There is a one to many relationship between data elements in the structure . Defines the hierarchical relationship .
Figure structure ： There is a many to many relationship between the data elements in the structure . Defines the network relationship .
1. Set structure ： There is no relationship between individual data elements （ A box of sugar ）.
2. Linear structure ： Defines the linear relationship , There is a one-to-one relationship between data elements .（ line up ）
3. A tree structure ： Defines the hierarchical relationship , There is a one to many relationship between data elements .（ Members of the family ）
4. Graphic structure ： Defines the network relationship , Data elements have many to many relationships .（ Bus stop ）
That is, how elements are stored , Storage structure is also called physical structure . It is for programmers . Storage structure It is divided into Sequential structure , The chain structure , Index structure , Hash structure .
1. Sequential storage structure : The logical structure between elements is represented by the relative position between data elements
2. Chain storage structure : The logical structure of array elements is represented by the pointers of elements between data elements
3. Hash storage structure : Sequential storage + Calculation column
4. Index storage structure : Sequential storage + Indexes
Logical structure and storage structure diagram ：
1. The operation of data
It is an operation algorithm defined on the logical structure of data , Such as searching 、 Insert 、 Delete 、 And sorting . for example , For the data structure of higher mathematics grade table , You can do a series of calculations ： Add a student record 、 Delete a student record 、 Find the average score of all students 、 The search sequence number is i Student scores, etc .
2. data type
It refers to a set of values with the same properties and some operations defined on this set . Data types can be divided into two categories ：
Type of atom ： Basic types that can no longer be decomposed , integer 、 Real type 、 Character type, etc .
Structure type ： A combination of several types , Can be decomposed again .
[1]:https://baijiahao.baidu.com/s?id=1687302279709228125
[2]: data structure ： A complete collection of eight data structures _ Green water flows long *z The blog of -CSDN Blog _ data structure
[3]: https://blog.csdn.net/heyuchang666/article/details/49891635
Online notes of Python major course of Hangzhou Teachers management department (V): Supplementary Exercises of basic python (30 cases compiled by ourselves)
notes ： The title has been ada
Enumerate usage and zip usage in Python: parallel traversal, collection usage and characteristics
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