Calculate the execution time of second

cost_s.c

/* use time() to calculate the execution time in second */
#include <time.h>
long timecost(void (*dosomething)())
{
	time_t start, end;
	long cost;

	start = time(NULL);
	dosomething();
	end = time(NULL);
	cost = (int)difftime(end, start);
	printf("cost time: %ld seconds", cost);

	return cost;
}