Article directory Summary 1.memcpy 1.1 Function introduction 1.2 Simulation implementation 2.memmove 2.1 Function introduction 2.2 Simulation implementation 3. memset 3.1 Function introduction 4.memcmp 4.1 Function introduction Abstract This article introduces commonly used memory operation functions in C language, including memcpy, memmove, memset and memcpy. These functions handle the copying, moving, and initialization of memory data. […]
Tag: memset
Do you really understand memory functions (memcpy, memmove, memset, memcmp)?
Blog homepage: Jiang Chijun’s blog ?Inclusion column: The road to advanced C language Column recommendation: ?Beginner’s road to C language ?Exploration of data structure Code repository: Jiang Chijun’s code repository Everyone is welcome to likeCommentCollect? Article directory 1.memcpy function 1.1 [Notes]: 1.2【Example】 Simulation implementation of memcpy 2.memmove function 2.1 [Notes]: 2.2【Example】 Simulation implementation of memmove […]
[Algorithm Notes] C(n,m) does not cross the boundary but A(n,m) crosses the boundary; C(n,1)+C(n,3)+C(n,5)… and other binomial theorems; ‘memset’: identifier not found
https://codeforces.com/contest/893/problem/E Solution where C(n,m) does not cross the boundary but A(n,m) crosses the boundary C(n,m) = A(n,m) / (n-m)! This question requires modulo 1e9 + 7, but only addition, subtraction, and multiplication can modulate it, but division cannot. Therefore, this A(n,m) needs to store the original value. The original value is too large and becomes […]
[C language memory function selection] memcpy, memset, memmove and simulation implementation! Master the art of memory manipulation!
[C language memory function selection] memcpy, memset, memmove and simulation implementation! Master the art of memory manipulation! 1. memcpy 1.1 Introduction to the use of memcpy 1.2 Simulation implementation of memcpy 2. memmove 2.1 Introduction to the use of memmove 2.2 Simulation implementation of memmove 3. memcmp 3.1 Introduction to the use of menmcmp 4. […]
Memory functions (memcpy, memmove, memcmp, memset)
This article mainly introduces the simulation implementation of some commonly used memory functions and some functions in C language. The following functions all need to include the header file: Directory 1. The memcpy function 1. Function introduction 2. Simulation implementation of memcpy Two, memmove function 1. Function introduction 2. Simulation implementation of memmove Three, memcmp […]
C language: character functions and string functions (memory operation functions memcpy, memmove, memset, memcmp+ simulation implementation) part two
Directory foreword 1. Memory operation function: memcpy Simulate the implementation of memcpy: Second, the memory operation function: memmove Simulate the implementation of memmove: Three, memory operation function: memset Simulate the implementation of memset: Fourth, the memory operation function: memcmp Simulate the implementation of memcmp: Foreword Find the length of the string: (explained in the previous […]
Memory operation functions memcpy, memmove, memcmp, memset
Memory operation function one.memcpy Function Introduction void * memcpy ( void * destination, const void * source, size_t num ); 1. Function function: copy the data of the first num bytes of the space pointed to by the source to the destination 2. Don’t care about ‘\0’, it will not stop because of ‘\0’, it […]
memchr, memset, memmove, memcpy, memcmp under the string.h file, and custom implementation of the same function
Directory One, memchr Two, memset Three, memmove Four, memcpy 5. memcmp Custom implementation: 1. memchr Two, memset 3. memmove 4. memcpy Five, memcmp One, memchr This function is used to find whether there is a certain number in the data (directly search for bytes) memchr usage: Function declaration: Parameters of the function: memchr example: int […]
Memset(addr, 0, size) causes Bus error problem analysis
Demo code that caused the problem #define SH_DEV_MEM “/dev/mem” #define myerror printf // Get device physical memory mapped by mmap static void *mymmap(u32 offset, u32 size, u8 is_rd_only, u8 is_clear) { void *ptr; s32 fd; offset = 0x45E00000; size = 0x1000; is_rd_only = 0; is_clear = 1; /* open the shared memory object */ // […]
CPP – comparison between memset and for loop assignment initial value
When writing the code, I thought for a while whether the initialization of memset is faster or the initialization of for loop is faster.After reading a large amount of literature, the conclusions are as follows: If an initial value is assigned to an array, memset is definitely faster than a for loop The initial value […]