CLOCKS_PER_SEC
#define CLK_TCK CLOCKS_PER_SEC
#define MICROSECONDS_PER_CLOCK_TICK (1000000 / CLOCKS_PER_SEC)
while ((clock() - start) < CLOCKS_PER_SEC / 4)
seconds = (end - start) / (float) CLOCKS_PER_SEC;
while ((clock() - start) < CLOCKS_PER_SEC / 4)
seconds = (end - start) / (float) CLOCKS_PER_SEC;
while ((clock() - start) < CLOCKS_PER_SEC / 4)
seconds = (end - start) / (float) CLOCKS_PER_SEC;