Programmer Think

preface As we all know, numpy library is the basic library of scientific computing. We learned earlier that the numpy ndarray object requires the homogeneity of data elements in the array. At the same time, the memory space of numpy array element values is the same, and the bottom layer adopts two storage methods: C-order (row first storage) o ...

1. If the annual growth rate of China's gross national product is 9%, calculate the percentage increase of China's gross national product in 10 years. The calculation formula is p = (1 + r) ^ n, r is the annual growth rate, n is the number of years, and P is the multiple compared with now #include<stdio.h> #include<stdlib.h> #i ...

array 1. Creation and initialization of one-dimensional array Array; A collection of elements of the same type. How to create an array: type_t arr_name [const_n]; //type_t is the element type of the index group //const_n is a constant expression that specifies the size of the array Instance of array creation: //Code 1 int arr1[ ...

0. Preface The processing of characters and strings in C language is very frequent, but C language itself has no string type. Strings are usually placed in constant strings or character arrays. String constants apply to string functions that do not modify them 1. Function introduction strlen #include<stdio.h> #include<asse ...

After we understand inheritance, we all know the characteristics of inheritance. 1: Single inheritance (a son can only have one father) 2: Multi level inheritance (son inherits father, father inherits grandfather) Therefore, the disadvantages of inheritance are obvious. The inheritance of Java language is single inheritance!! Therefore, in ...

catalogue aggregate​ Collection interface Generics Generic erasure mechanism Considerations for using generic arrays Forced conversion of object array aggregate The collection of Java is like a container, which is specially used to store the references of objects. These objects can be of any data type and variable length. These collect ...

Common dependency 1. Pring context dependency <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>5.3.13</version> </dependency> 3.junit <dependency> <groupId>junit</groupId> <artifactId>junit</artifactI ...

When you first know Python language, you feel that Python meets all the requirements for programming language when you go to school. The efficient programming skills of Python language make those who have been forced to learn c or c + + for four years excited and finally relieved. High level language, if you can't do this, what's high level? 0 ...

Mybatis actual combat Tip: you can add the directories of all articles in the series here. You need to add the directories manually For example: the first chapter is the use of pandas, an introduction to Python machine learning Tip: after writing the article, the directory can be generated automatically. For how to generate it, please refer ...

The last one was "Spring Boot - custom Banner pattern", and this one is "smoother MyBatis". MyBatis's strength comes from its vast ecology and the support of many large domestic factories. - the plass are gone From iBatis to MyBatis, and then to many peripheral tools typically represented by MyBatis Plus in domestic tea ...