Performance loss caused by Linq [duplicate]
You forgot to reset the Stopwatch after foreach
performance
optimized sum of an array of doubles in C [duplicate]
I posted an improved version of this answer on a duplicate of this: C loop optimization help for final assignment. It was originally just a repost, but then I made some changes to answer the differences in that question. I forget what’s different, but you should probably read that one instead. Maybe I should just … Read more
What is the fastest search algorithm for a list with names and numbers
Pseudo code, find last O(log N) of each name O(M). auto it = vec.begin(); while (it != vec.end()) { // O(M) auto last = find_last_with_same_name(it, it->name); sum += last.value; it++; } Use exponential_search for O(log N) for finding the last and therefore largest value. For a total of O(M log N). If M, the number … Read more
Is doing multiplication multiple times or assigning to a variable faster?
Just so we can end this already, here is the answer. Using timeit on my computer we get the results as… Do the multiplication in the loop every time: $ python -m timeit ‘for _ in xrange(10): 10 * 20 > 0’ 1000000 loops, best of 3: 1.3 usec per loop Do the multiplication outside … Read more
Which yields faster code?
The true answer to your question is: “depends on the platform and compiler settings”. Let us take the case of no optimizations. There are 3 cases. Case 1: Adding the variable 3 times. The instructions: MOV Y, 0 ; Set Y to zero. ADD Y, Y, X ; Add X to Y and place result … Read more
PHP: What’s the speed difference “template” vs “quote”? [duplicate]
Let’s find out: <?php ob_start(); $a = 0; $time1 = microtime(true); for ($i = 0; $i < 100000; $i++) { echo “<html><body>$a</body></html>”; } $time2 = microtime(true); for ($i = 0; $i < 100000; $i++) { ?> <html><body><?php echo $a; ?></body></html> <?php } $time3 = microtime(true); ob_end_clean(); echo ‘Just echo: ‘ . ($time2 – $time1) . … Read more
Website is very slow, but if I modify the URL it loads normally
I am not sure what’s going on here because your question lacks a little detail. But just to make the scenario clear when it comes to Client/ Server side and accessing something on the web with a domain. You have to understand that whatever lags you experience it always points to a certain process that … Read more
jQuery: load pages with ajax, caching, clean URLs and back button support
Try turbolinks or pjax. https://github.com/rails/turbolinks/ http://pjax.heroku.com The only missing part is the fade in / fade out callbacks, which can be inserted with listen events for either.
Convert JSON to array in Javascript
You could splice the values and get only the first two elements as number. var array = [{ time: “18:00:00” }, { time: “10:00:00″ }, { time:”16:30:00” }], result = array.map(o => o.time.split(‘:’).slice(0, 2).map(Number)); console.log(result); .as-console-wrapper { max-height: 100% !important; top: 0; } If you have JSON sting, then you need to parse it with … Read more
Where is likely the performance bug here? [closed]
Lazy evaluation will not make bad algorithms perform better. It will just delay when those performance problems will affect you. What lazy evaluation can help with is space complexity, i.e. reducing the amount of memory you need to execute your algorithm. Since the data is generated lazily, you will not (necessarily) have all the data … Read more