execution time of c program

Execution Time of a C Program

The execution time of a C program can vary depending on various factors such as the complexity of the program, the hardware on which it is running, and the efficiency of the compiler. In general, the execution time of a C program can be measured using various techniques, including:

Using the time command: On Unix-like systems, you can use the time command to measure the execution time of a C program. Simply prepend the time command before running the program, like this: time ./program. The output will include the real, user, and system time taken by the program.
Using the clock function: The clock function from the <time.h> header can be used to measure the CPU time taken by a C program. You can call clock at the beginning and end of your program and calculate the difference to get the execution time. Here's an example:

```c #include #include

int main() { clock_t start = clock();

   // Your program code here

   clock_t end = clock();
   double execution_time = (double)(end - start) / CLOCKS_PER_SEC;
   printf("Execution time: %f seconds\n", execution_time);

   return 0;

} ```

This code measures the execution time in seconds using the clock function and prints it to the console.

Using profiling tools: Profiling tools like gprof can provide detailed information about the execution time of different parts of a C program. These tools can help identify performance bottlenecks and optimize the code accordingly.

It's important to note that the execution time of a C program can also be influenced by external factors such as the operating system's scheduling algorithm and the presence of other running processes.