how to speed up c++ code

• Use better compilers, and turn on the optimizer.
• Use optimal algorithms.
• Use better libraries, and use libraries better.
• Reduce memory allocation.
• Reduce copying.
• Remove computation.
• Use optimal data structures.
• Increase concurrency.
• Optimize memory management.

Full Answer

How can I Make my C++ code compile faster?

But at a fundamental level, the key way to make your C++ code compile faster is to limit the number of #includes<> you have in your source files. This means the compiler is processing fewer lines of code, and thus your total compile times will go down.

How can I speed up my programming?

Sometimes you will have a very long expression composed of many conditions, one could use function that will return true or false, but functions are expensive, they use stack and few copies could be created, if possible you could use a macro or a macro with a variable to increase the speed and create code that will be more easy to maintain.

How to optimize your code to make it run faster?

There is always more room for improvement to make your code run faster. Sometime we can use certain programming tricks to make a code run faster at the expense of not following best practices such as coding standards, etc. Try to avoid implementing cheap tricks to make your code run faster. 1. Optimize your Code using Appropriate Algorithm

Should I use C or printf in C++ to increase speed?

From point of security, cout and cin would be considered as better option for files, as you would have adequate instructions in fstream header. If you use C or printf in C++ you should consider some other functions that could even more increase the speed of your program. For strings you could use puts, gets or their equivalents for file operations.

What is Optimisation in C?

Optimization is a program transformation technique, which tries to improve the code by making it consume less resources (i.e. CPU, Memory) and deliver high speed. In optimization, high-level general programming constructs are replaced by very efficient low-level programming codes.

Does C++ run faster than C?

Performance is slow compared to C++. C++ language is an object-oriented programming language, and it supports some important features like Polymorphism, Abstract Data Types, Encapsulation, etc. Since it supports object-orientation, speed is faster compared to the C language.

How do you write a optimal code?

We say that code optimization is writing or rewriting code so a program uses the least possible memory or disk space, minimizes its CPU time or network bandwidth, or makes the best use of additional cores. In practice, we sometimes default to another definition: Writing less code.

What is speed optimized code?

< Optimizing Code for Speed. Optimization is the term that is applied to the process in which code is tuned to be better in some respects: either speed, memory consumption, input/output (disk read and writes or network reads and writes), etc.

Which is faster C or Python?

C is a faster language compared to Python as it is compiled. Python programs are usually slower than C programs as they are interpreted. In C, the type of the various variables must be declared when they are created, and only values of those particular types must be assigned to them.

Is C# or C++ faster?

C++ code is much faster than C# code, which makes it a better solution for applications where performance is important. For instance, your network analysis software might need some C++ code, but performance is probably not a huge issue for a standard word processing application coded in C#.

How can I speed up my algorithm?

Most Common Ways To Speed up an algorithmReplace a nested loop by first building a hash and then looping.Remove unnecessary accumulations.Cache intermediate or previous results.Zip merge.

How do I optimize my C# code?

5 Ways to Optimize your C# CodeBenchmark your code. ... Avoid string based conversions — they'll slow down your code a lot. ... Check for empty strings using string. ... Use arrays. ... Finally: simplify your code.

How do you write a professional code?

11 Tips to Write Better Code1) Decide on the indentation and keep it that way.2) Make comments.3) Consistent name scheme.4) Don't repeat code.5) Avoid writing long code lines.6) Break down a big task into smaller chunks.7) Organize your program into smaller files.8) Write clever code that is also readable.More items...•

What is code performance?

What Is the Performance of Code? Wiktionary says that performance is “the amount of useful work accomplished estimated in terms of time needed, resources used, etc.” In the context of this article, the time needed directly depends on how the code uses the CPU, and the resources used refer to the computer memory.

Why code optimization is needed?

Optimizing code is similar to buying a faster car. As a result, our code executes more rapidly, and our site or application consumes less memory than before. Although the optimization process may require additional time and money, the result is a better experience, not just for developers but also for end users.

What is runtime performance?

Runtime performance is how your page performs when it is running, as opposed to loading.

How to improve C++ performance?

10 Tips for C and C++ Performance Improvement Code Optimization 1 Security of the program 2 Memory consumption 3 Speed of the program (Performance Improvement)

Why is it harder to read code?

It is way harder to read code this way, but it will increase the speed of program. In other words, when you don’t use better algorithm, but your program still runs faster, the increased speed might be due to better syntax that will generate faster code.

What is machine code?

Well, when you finish your code it will translate in some assembler and then into something that is called machine code. Each operation is performed in processor or in some other part of computer like mathematical coprocessor or in graphic card or something similar.

What are some basic operations that slow down a program?

Most basic operations like +=, -=, and *=, when applied on basic data types could slow down the program as well. To be sure you will need to know how it gets transformed into assembler on your computer.

When to use "if" in code?

In “if”, you usually have tests and that could produce code that is bit slower.

Can you use printf in C++?

If you use C or printf in C++ you should consider some other functions that could even more increase the speed of your program.

Can you code with add move from assembler in C++?

Bit operators, and tricks that go with them could increase the speed of program, but you should be very careful because you could end up with machine dependant code and that is something to avoid. To be sure, you could still code with add move from assembler in C++.

How fast is a CPU in kernel mode?

2.7 times faster in number of CPU-seconds that the process spent in kernel mode.

What is the path to CMAKE_C_COMPILER?

We use fully qualified paths to the compilers we want to use by specifying CMAKE_C_COMPILER=/usr/bin/gcc and CMAKE_CXX_COMPILER=/usr/bin/g++ . See the next section about masquerading to understand why we do this.

Is C++ code wise?

In terms of C++, I don’t expect anything code-wise except that your project uses CMake and compiles with GCC or Clang.

What is the purpose of code optimization?

There are two phases of code optimization. The first is to eliminate unnecessary run-time cycles by using efficient algorithms. The second is to accomplish each of the necessary operations in as little time as possible without sacrificing too much development time or code clarity.

Why do we break up code into functions?

In many cases a piece of code is broken up into functions to eliminate typing duplicate code and to make things easily modifiable and readable. However, the use of macros will do the same thing, and, since they arc resolved at compile time, they require absolutely no run-time overhead! There is one thing to remember about using #define macros. When passing arguments to macros, whatever you give as an argument will be literally replaced when the macro is expanded. For example:

Can C be faster than assembly?

The C programming language is famous for its ability to produce speedy and efficient code, but it still can't beat assembly, right? Wrong! If you optimize your code using these techniques, you can get assembly-fast results without losing the power of C.

Can compilers catch simple cases?

Most compilers will catch this simple case, but you might as well do it yourself, just in case the compiler doesn't.

What does speeding up a program mean?

Speeding up a Program is just improving the Time Complexity of that Program.

How to avoid cin/cout?

Avoid cin/cout, use scanf/printf at any cost. Cin/Cout are extremely time consuming functions. If you want even better performance use getchar_unlocked. This article explains it pretty well : Really Fast I/O methods for Programming in C++

What is a namespace in C++?

namespaces are an under-used superpower of C++ and can do wonders to organize a codebase and make terribly messy specializations very clean and easy to deal with. If any user code is defined in the std namespace it should be taken out and put in its own; std is for the STL.

What is the purpose of solving time constraints?

Solve Problems in Time Constraints, this practice will help you to generally think of a faster solution.

Can dynamic programming speed up problems?

General tip (irrespective of C++): Dynamic programming can speedup some problems by good amount.

Can Visual Studio optimize for space?

General tip (irrespective of C++) : Check compilation options - e.g. in visual studio you can optimize for space/ speed. This is easy and takes almost no time to try.

Is merge sort fast?

Like for sorting there are various techniques, but Merge Sort and Quick Sort are quite fast ( O (NLog (N) ) Complexity) , Similarly there are thousands of Algo’s to make your program run faster, depending upon the constraints of the program.

What is the shortcut for copying text?

This can give you a 2–3 minutes advantage which is always welcomed. Keyboard Shortcuts: Some of the useful ones are: Ctrl + Shift + D: When used without anything selected, your current line duplicates, and if used with something chosen, the chosen text duplicates. Example of Shortcut Ctrl + Shift + D.

What text editor do I use for MinGW?

I use a Windows Machine with MinGW, and the text editor of choice is vanilla Sublime Text with some minor customizations. If you want to have a similar setup, link to a tutorial at the end of the article.

How long does it take to save headers?

Pre-compiled headers can save up to 3–5 seconds every time you run your program which may sound much but if in a contest you compiled and ran your codes for 20 times, effectively you saved around 1:30 minutes which sometimes can be the difference between solving the last problem and not being able to complete it.

Can you write a macro to shorten it to FOR?

So a solution is to write a macro that can just shorten it to FOR (i,N) It not only can help you code faster but also makes your code visually less cluttered, which can help in debugging.

Can you use brackets in C++?

You can also have a look at my template to have a better idea ( LINK ). No Brackets for Single line statements: In C++, you can save you a split second or, more importantly, can make your code a bit cleaner by skipping the brackets if you want to write a single statement in a loop or an if statement.