Programming VIP

Deep understanding of pointers preface First, let's understand the concept of the following pointers: A pointer is a variable used to store an address, which identifies a piece of memory space.The size of the pointer is fixed at 4 or 8 bytes (32 or 64 bits).Pointers are typed, which determines the step size of pointer operation and t ...

Clause 05: understand which functions are written and called by default in C + + When you don't write it yourself, the compiler will create default constructor, destructor, copy constructor and copy assignment operator for your class by default. For example: class Empty{}; In fact, it's equivalent to class Empty{ public: Empty(){...} //d ...

1, Title [LeetCode-21] Merge the two ascending linked lists into a new} ascending linked list and return. The new linked list is composed of all nodes of a given two linked lists.   Example 1: Input: l1 = [1,2,4], l2 = [1,3,4] Output: [1,1,2,3,4,4] Example 2: Input: l1 = [], l2 = [] Output: [] Example 3: Input: l ...

Chapter 16 Templates and Generic Programming Define Template Function Template template<typename T> int compare(const T &v1, const T &v2) { if(v1 < v2) return -1; if(v2 < v1) return 1; return 0; } Template definitions start with the keyword template followed by a list of template paramete ...

preface Blue Bridge Cup group B 2017 provincial competition blank filling question (C + +) 1, Title Description A batch of precious metal raw materials are neatly stacked in the high-tech laboratory of Planet X. The shape and size of each metal raw material are exactly the same, but the weight is different. Metal materials are strictl ...

1. Learning goals and plans? 2. Learning vi, grep awk, sed and some Linux commands 1. grep: Searches for files in the specified directory and manipulates the results, suitable for simply finding matching text 1.grep after test.log > res.log: in test. Find the row with the after keyword in the log and save it in res.log 2.find-name'* ...

IO File mode in: read when opening a file; out: write when opening a file (empty the file stream existing in the cloud by default); app: find the end of the file before each write (the current file data will not be cleared); ate: locate the file at the end of the file immediately after opening the file; trunc: empty the existing file stream wh ...

preface How does C/C + + code become a program that can run on hardware? Let's start with a simple "Hello World" program. Hello World compilation There is a popular joke: A programmer was very interested in calligraphy and decided to make achievements in this field after retirement. So he spent a lot of money to buy the first-clas ...

438. Find all letter words in the string Meaning: Given two strings S and p, find the substrings of all ectopic words of p in s, and return the starting indexes of these substrings. The order in which answers are output is not considered. Ectopic words refer to strings with the same letters but arranged differently. Example 1: input: ...

**Read only variable * * readonly var **Delete variable * * unset var Variable type: Local variables are defined in scripts or commands and are only valid in the current shell instance Environment variable a variable that can be accessed by all programs Shell variable is a variable specially set by the shell program Single quotatio ...