I'm building a website application that will have two different types of users, let's call one A and the other is B . They have some similar data, such as: 'name', 'password', etc., and the rest are different. I have done 2 tables for them separately because I need it like that, but I have an idea and I'm not sure whether I can do it! The idea is that when the user
我建立，将有两种不同类型的用户的web应用程序，让我们叫一个A ，另一个是B 。 他们有一些类似的数据，例如：'name'，'password'等，其余的不同。 我为他们单独做了两张桌子，因为我需要这样做，但我有一个想法，我不确定我是否可以做到这一点！ 这个想法是，当用户进入注册页面时，他们会看到一个注册表单，其中包含A和B之间相似的数据，然后我会让用户检查一个复选框，指出它是A用户还是B用户。 根据他们
I'm making an interval collection extension of the famous C# library C5. The IInterval interface defines an interval with comparable endpoints (irrelevant members removed): public interface IInterval<T> where T : IComparable<T> { T Low { get; } T High { get; } } This works well in general, since interval endpoints can be anything comparable like integers, dates, or even
我正在对着名的C＃库C5进行间隔集合扩展。 IInterval接口定义了具有可比较端点的间隔（不相关的成员被删除）： public interface IInterval<T> where T : IComparable<T> { T Low { get; } T High { get; } } 这通常适用，因为间隔端点可以是任何类似整数，日期甚至字符串的任何东西。 但是，有时可以计算间隔的持续时间。 间隔[3:5)的持续时间为2，间隔[1PM, 9PM)的持续时间为8小时。 这对于可比较
Possible Duplicate: What's a good algorithm to determine if an input is a perfect square? I want Shortest and Simplest way to Check a number is perfect square in C# Some of Perfect Squares: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, ...... Probably checking if the square root of the number has any decimal part, or if it is a whole number. Implementationwise, I would consider something li
可能重复： 什么是一个很好的算法来确定输入是否是一个完美的正方形？ 我想要最简单最简单的方法来检查一个数字是完美的C＃ 一些完美的广场： 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, ...... 可能检查数字的平方根是否有小数部分，或者是否是整数。 在实施方面，我会考虑这样的事情： double result = Math.Sqrt(numberToCheck); bool isSquare = result%1 == 0; isSquare现在对于所有方块都是true对于其他所有方块
Is a switch statement actually faster than an if statement? I ran the code below on Visual Studio 2010's x64 C++ compiler with the /Ox flag: #include <stdlib.h> #include <stdio.h> #include <time.h> #define MAX_COUNT (1 << 29) size_t counter = 0; size_t testSwitch() { clock_t start = clock(); size_t i; for (i = 0; i < MAX_COUNT; i++) { sw
switch语句实际上比if语句快吗？ 我使用/Ox标志在Visual Studio 2010的x64 C ++编译器上运行以下代码： #include <stdlib.h> #include <stdio.h> #include <time.h> #define MAX_COUNT (1 << 29) size_t counter = 0; size_t testSwitch() { clock_t start = clock(); size_t i; for (i = 0; i < MAX_COUNT; i++) { switch (counter % 4 + 1) { cas
Yesterday I found an article by Christoph Nahr titled ".NET Struct Performance" which benchmarked several languages (C++, C#, Java, JavaScript) for a method which adds two point structs ( double tuples). As it turned out, C++ version takes about 1000ms to execute (1e9 iterations), while C# cannot get under ~3000ms on the same machine (and performs even worse in x64). To test it myse
昨天我发现了Christoph Nahr的一篇题为“.NET结构性能”的文章，该文章针对添加了两个点结构（ double元组）的方法对几种语言（C ++，C＃，Java，JavaScript）进行了基准测试。 事实证明，C ++版本需要大约1000ms才能执行（1e9次迭代），而C＃在同一台机器上不能低于〜3000ms（并且在x64中表现更差）。 为了自己测试它，我使用了C＃代码（稍微简化为仅调用参数按值传递的方法），然后在i7-3610QM机器上运行（3.1Ghz boost for
I studied like malloc uses the sbrk system call. But, some one says, the sbrk is deprecated one. Now a days malloc using the mmap2 system call to allocate memory. So, Is there any commands like (ls,cat, grep, sed) using the sbrk system call. For Ex: mohanraj@ltsp63:~/Development/chap8$ strace -c ls a.out files flush.c fopen.c ld.c lld.c malloc.c opendir1.c t2.c t3.c t.c test.c
我学习像malloc使用sbrk系统调用。 但是，有人说，sbrk已被弃用。 现在使用mmap2系统调用分配内存的天malloc。 那么，是否有像（ls，cat，grep，sed）这样的使用sbrk系统调用的命令。 例如： mohanraj@ltsp63:~/Development/chap8$ strace -c ls a.out files flush.c fopen.c ld.c lld.c malloc.c opendir1.c t2.c t3.c t.c test.c % time seconds usecs/call calls errors syscall ------ -----
Seems like even after I free all the memory for a Linux process that was allocated by malloc(), memory is still reserved for the process and not returned to the OS. Running valgrind massif tool by default revelas no leakges. Running valgrind with --pages-as-heap=yes reveals this: ->13.77% (7,655,424B) 0x35FEEEB069: brk (brk.c:31) ->13.77% (7,655,424B) 0x35FEEEB113: sbrk (sbrk.c:53)
似乎即使我释放了由malloc（）分配的Linux进程的所有内存后，内存仍保留用于进程而不返回到操作系统。 运行valgrind massif工具默认情况下没有泄漏。 使用--pages-as-heap = yes运行valgrind会显示： - > 13.77％（7,655,424B）0x35FEEEB069：brk（brk.c：31） - > 13.77％（7,655,424B）0x35FEEEB113：sbrk（sbrk.c：53） - > 13.77％（7,655,424B）0x35FEE82717：__default_morecore（morecore.c：48）
According to Linux programmers manual: brk() and sbrk() change the location of the program break, which defines the end of the process's data segment. What does the data segment mean over here? Is it just the data segment or data, BSS, and heap combined? According to wiki: Sometimes the data, BSS, and heap areas are collectively referred to as the "data segment". I see no
根据Linux程序员手册： brk（）和sbrk（）更改程序中断的位置，该中断定义了进程数据段的结尾。 数据段在这里意味着什么？ 它只是数据段或数据，BSS和堆的组合？ 根据维基： 有时数据，BSS和堆区统称为“数据段”。 我没有理由改变数据段的大小。 如果它是数据，BSS和堆集体然后它是有道理的，因为堆将获得更多的空间。 这让我想到了第二个问题。 在我读到的所有文章中，作者说，堆向上增长，堆栈向下增长。 但是
I have a doubt regarding heap in program execution layout diagram of a C program. I know that all the dynamically allocated memory is allotted in heap which grows dynamically. But I would like to know what is the max heap size for a C program ?? I am just attaching a sample C program ... here I am trying to allocate 1GB memory to string and even doing the memset ... #include <stdio.h
我对C程序的程序执行布局图中的堆有疑问。 我知道所有动态分配的内存都被分配到动态增长的堆中。 但是我想知道C程序的最大堆大小是多少？ 我只是附加一个示例C程序...在这里，我试图分配1GB的内存字符串，甚至做memset ... #include <stdio.h> #include <string.h> #include <stdlib.h> int main(int argc, char *argv[]) { char *temp; mybuffer=malloc(1024*1024*1
Given this C program where the private virtual memory is printed: #include <stdio.h> #include <stdlib.h> #define _PSTAT64 #include <sys/param.h> #include <sys/pstat.h> #include <sys/unistd.h> void pstatvm() { struct pst_vm_status pst; int idx, count; long long shared_vm = 0; long long shared_ram = 0; long long private_vm = 0; lon
鉴于此C程序打印私人虚拟内存： #include <stdio.h> #include <stdlib.h> #define _PSTAT64 #include <sys/param.h> #include <sys/pstat.h> #include <sys/unistd.h> void pstatvm() { struct pst_vm_status pst; int idx, count; long long shared_vm = 0; long long shared_ram = 0; long long private_vm = 0; long long private_ram = 0; pid_t