Measure execution time in C++ OpenMP code

Question

I am running a .cpp code (i) in sequential style and (ii) using OpenMP statements. I am trying to see the time difference. For calculating time, I use this:

Answer 1

#include "ctime"

std::time_t start, end;
long delta = 0;
start = std::time(NULL);

// do your code here

end = std::time(NULL);
delta = end - start;

// output delta