Why is CLOCKS_PER_SEC not the actual number of clocks per second?
clock returns the amount of time spent in your program. There are 1,000,000 clock ticks per second total*. It appears that your program consumed 60% of them. Something else used the other 40%. *Okay, there are virtually 1,000,000 clock ticks per second. The actual number is normalized so your program perceives 1,000,000 ticks.