modulo

问题 I have a question regarding hashtable size and modular hashing. The hashing algorithm I'm referring to is the following: hash_key % table_size = array_index. I'm reading an algorithms textbook where the following bit of advice is given: If the table size is not prime, it may be the case that all of the bits of the key do not play a role in determining the array_index. Can anyone explain what this means exactly with an example? 回答1: What you want to avoid is common factors. There is a theorem

问题 I was in the middle of coding a slideshow in javascript using jquery, when I ran into something that was doing what my several lines of code was doing in a couple lines. Problem is, I don't comprehend how it works so I can modify it. var imgs = [ 'image1.jpg', 'image2.jpg', 'image3.jpg']; var cnt = imgs.length; $(function() { setInterval(Slider, 4000); }); function Slider() { $('#imageSlide').fadeOut("slow", function() { $(this).attr('src', imgs[(imgs.length++) % cnt]).fadeIn("slow"); }); }

问题 For a given b and N and a range of a say (0...n) , I need to find ans(0...n-1) where, ans[i] = no of a's for which pow(a, b)modN == i What I am searching here is a possible repetition in pow(a,b)modN for a range of a , to reduce computation time. Example:- if b = 2 N = 3 and n = 5 for a in (0...4): A[pow(a,b)modN]++; so that would be pow(0,2)mod3 = 0 pow(1,2)mod3 = 1 pow(2,2)mod3 = 1 pow(3,2)mod3 = 0 pow(4,2)mod3 = 1 so the final results would be: ans[0] = 2 // no of times we have found 0 as

问题 If I have a string of length L=77 that I want to pad to a length that is a multiple of N=10. I am interested in computing just the amount of padding required. This can be easily done with N - (L % N) , except for cases where L % N is zero. I have been using the following for now: pad = (N - (L % N)) % N This does not seem particularly legible, so sometimes I use pad = N - (L % N) if pad == N: pad = 0 It seems overkill to use three lines of code for something so simple. Alternatively, I can

问题 i have a small issue trying to figure out how a modulo operation is being calculated. I am building up a queue, so i have a circular array. i cannot figure out how this modulo operation works. Given q: an array of Character of 5 elements length, The MAX constant gives the max length of the array "5" rare is an int which represents the first available spot in the array q public void enqueue(Character c)throws FullQueueException{ if(size()== MAX -1){ //if only 1 place left, is full, throw exc

问题 Modulo bias is a problem that arises when naively using the modulo operation to get pseudorandom numbers smaller than a given "upper bound". Therefore as a C programmer I am using a modified version of the arc4random_uniform() function to generate evenly distributed pseudorandom numbers. The problem is I do not understand how the function works, mathematically. This is the function's explanatory comment, followed by a link to the full source code: /* * Calculate a uniformly distributed random

问题 The modulo function in OCaml mod return results different when compared with the modulo operator in python . OCaml: # -1 mod 4 - : int = -1 Python: >>> -1 % 4 3 Why are the result different?. Is there any standard module function that operate as % in OCaml?. 回答1: Python is a bit different in its usage of the % operator, which really computes the modulo of two values, whereas other programming languages compute the remainder with the same operator. For example, the distinction is clear in

问题 I have a class which represents a shape. The Shape class has a property called Angle. I want the setter for this property to automatically wrap the value into the range [0,359]. Unfortunately, a simple _Angle = value % 360; only works for positive numbers. In C#, -40 % 360 == -40 . Google calc does it the way I want it. The value should be 320. What's the most elegant solution in C#? Here's the best way I've got so far: public double Angle { get { return _Angle; } set { if ( value >= 0 ) {

问题 I am seeking for a way to find modulo of a sequence of numbers like: (a1 + a2 + a3 + a4 + ... + an) mod x Is there any way/property of modulo function so that I can compute mod of this sequence from the individual mods of numbers in sequence. 回答1: As I can recall. you can: (a1 mod x + a2 mod x + a3 mod x + ... + an mod x) mod x Such equation will benefit one purpose. if the sum of the numbers exceeds the capacity of the variable used for summation. ex. 32 bit int. This way it is most probably

问题 I tried this - x=[2,3,4,7,9] count=0 for i in x: if i%2: count=count+1 print count why the count is 3 instead of 2 , as i%2 is satusfiying only for "2 and 4"? 回答1: The modulus of 2 over 2 is zero : >>> 2 % 2 0 So 2 % 2 produces 0 , which is a false value, and thus the if statement doesn't match. On the other hand, the modulus of 3 over to is one: >>> 3 % 2 1 1 is a non-zero integer, so considered true. In other words, the if i%2: test matches odd numbers, not even. There are 3 odd numbers in