Your analysis is not correct. Actually is CPU ALU unit dependent. 🙂 In first case you are using 4 bit integer but you forgotten that the highest bit of 4 bit sign integer is sign! So you are checking only the Carry and Overflow status and not also Negative status bit. In generally binary arithmetic … Read more
Because numbers in JavaScript are floating-point. They have limited precision. When JavaScript sees a very long number, it rounds it to the nearest number it can represent as a 64-bit float. In your script, start and end get rounded to the same value. alert(1234567890123456789); // says: 1234567890123456800 alert(1234567890123456799); // says: 1234567890123456800 There’s no built-in way … Read more
The easiest way is to actually write two functions, one which converts the day to a number of days from a given start date, then another which converts back to a date. Once the date is expressed as a number of days, it’s trivial to add or subtract to it. You can find the algorithms … Read more
Here is my contribution: c = b – ones(size(b))*diag(a) Now speed testing it: tic for i = 1:10000 c = zeros(size(b)); b = rand(7,3); c = b – ones(size(b))*diag(a); end toc The result: Elapsed time is 0.099979 seconds. Not quite as fast, but it is clean.
The whole reason we use 2’s-complement is that addition is the same whether the numbers are positive or negative – there are no special cases to consider, like there are with 1’s-complement or signed-magnitude representations. So to find A-B, we can just negate B and add; that is, we find A + (-B), and because … Read more
There are really two separate issues. The first is keeping the elements of the array in proper order so that there are no “holes” after removing an element. The second is actually resizing the array itself. Arrays in C are allocated as a fixed number of contiguous elements. There is no way to actually remove … Read more
A bit nicer is the following: $a = new DateTime(’08:00′); $b = new DateTime(’16:00′); $interval = $a->diff($b); echo $interval->format(“%H”); That will give you the difference in hours.
Taken from the docs here: Adds or subtracts the specified amount of time to the given calendar field, based on the calendar’s rules. For example, to subtract 5 days from the current time of the calendar, you can achieve it by calling: Calendar calendar = Calendar.getInstance(); // this would default to now calendar.add(Calendar.DAY_OF_MONTH, -5).
Short answer: No If it was a division or multiplication by powers of 2, you could use bitwise shift operators to make it faster, but in this case, nothing is better than x = 128 – x