processing-efficiency

I'm writing some code in Java where, at some point, the flow of the program is determined by whether two int variables, "a" and "b", are non-zero (note: a and b are never negative, and never within integer overflow range). I can evaluate it with if (a != 0 && b != 0) { /* Some code */ } Or alternatively if (a*b != 0) { /* Some code */ } Because I expect that piece of code to run millions of times per run, I was wondering which one would be faster. I did the experiment by comparing them on a huge randomly generated array, and I was also curious to see how the sparsity of the array (fraction of

I am looking for an efficient way to do the following: Using several source videos (of approximately the same length), I need to generate an output video that is composed of all of the original sources each running in its own area (like a bunch of PIP s in several different sizes). So, the end result is that all the original are running side-by-side, each in its own area/box. The source and output need to be flv and the platform I am using is Windows (dev on Windows 7 64bit, deployment to Windows server 2008). I have looked at avisynth but unfortunately it can't handle flv and non of the

Problem I am building a collage of photos from an array of images that I am placing onto a tableview. I want to make the images wrap when the number of images reaches the boundary of the tableview cell's width (this would allow me to display rows of images in the collage). Currently I get a single row. Please feel free to advise if additional information is required. I am most likely not approaching this in the most efficient way since there is a delay as the number of images used in the array begins to increase. (any feedback on this would be very much appreciated). Nota Bene I am creating a

This might sound like an obvious question but I just want to get some reassurance. Using Laravel's eager loading functionality, from what I understand it will create two queries to return a whole list of related results (say if you're working with two tables). However, and correct me if I'm wrong, using a join statement will leave you with only one query , which creates one less round trip to the server's database (MySQL) and is a more efficient query. I know that you can write join queries in Laravel, which is great, so the question is: am I incorrect to assume that when retrieving related

Question: Given an unsorted array of positive integers, is it possible to find a pair of integers from that array that sum up to a given sum? Constraints: This should be done in O(n) and in-place (without any external storage like arrays, hash-maps) (you can use extra variables/pointers) If this is not possible, can there be a proof given for the same? If you have a sorted array you can find such a pair in O(n) by moving two pointers toward the middle i = 0 j = n-1 while(i < j){ if (a[i] + a[j] == target) return (i, j); else if (a[i] + a[j] < target) i += 1; else if (a[i] + a[j] > target) j -=