Let's say I have a Java ArrayList, that is sorted. Now I would like to find the index of value x. What would be the fastest (without more than 30 lines of code) way to do this? Use of the IndexOf() method? Iterate through all values in a simple for loop? Use of some cool algorithm? We are talking about around let's say 50 integer keys. ...
What is generally the fastest algorithm to recursively make a directory (similar to UNIX mkdir -p) using the FTP protocol? I have considered one approach: MKDIR node if error and nodes left go to 1 with next node end But this might have bad performance if part of the directory most likely exists. For example, with some amortization...
I have a set of positive numbers. Given a number not in the set, I want to find the next smallest and next largest numbers that are in the set. The only way I can think to do it now is to find the next smallest by decreasing by 1 until I find a number in the set, and then do the same for finding the next largest. Motivation: I have a bu...
I am writing a program which will tokenize the input text depending upon some specific rules. I am using C++ for this. Rules Letter 'a' should be converted to token 'V-A' Letter 'p' should be converted to token 'C-PA' Letter 'pp' should be converted to token 'C-PPA' Letter 'u' should be converted to token 'V-U' This is just a sample...
Given a string, figure out how many characters minimum are needed to make the word a palindrome. Examples: ABBA : 0 (already a palindrome) ABB: 1 FAE: 2 FOO: 1 ...
Or to ask it another way, how OnEraseBkgnd() works? I'm building a custom control and I hit on this problem. Childs are rectangles, as usual. I had to disable OnEraseBkgnd() and I use only the OnPaint(). What I need is to efficiently clear the area behind the childs and without flickering. Techniques like using back buffers are not an o...
I've implemented file compression using huffman's algorithm, but the problem I have is that to enable decompression of the compressed file, the coding tree used, or the codes itself should be written to the file too. The question is: how do i do that? What is the best way to write the coding tree at the beggining of the compressed file? ...
I have got many Strings. All of them contain only characters. Characters and words are not splittet with a space from each other. Some of the characters form english words and other just bufflegab. The Strings may not contain a whole sentence. I need to find out which of them are written in valid english speech. What I mean with that is...
It seems that there are several really fast prime factorization algorithms around (one that looks ideal is quadratic sieving). However, rather than make my own (likely poor) implementation I would like to use a ready-made library for simplicity. I need to be able to factor integers of up to 15 digits efficiently. Because of that, I'm no...
How to find an algorithm for calculating the sum value in the array?? Is is Something like this? Algorithm Array Sum Input: nonnegative integer N, and array A[1],A[2],...,A[N] Output: sum of the N integers in array A Algorith Body: j:=1 sum:=0 while j<N sum := sum + a[J] j:=j+1 end while end Algorithm Array Sum And how ...
I'm looking for a robust face detection algorithm/library, preferably in C (C++ is okay too; other languages I can port if necessary). I've used OpenCV's implementation in the past, but I don't think it's invariant to rotation. Doesn't need to be real-time, but it shouldn't be horrendously slow either (maybe one or two seconds per photo ...
Possible Duplicates: Books on Design Patterns and/or Algorithms? How to get started on ALGORITHMS? What is the best book for learning about Algorithms? I am planning to get some knowledge about Data Structure and Algorithms. Also I have a reasonable knowledge on Discrete Mathematics. Would Art of Computer Programming be a ...
Which algorithm would you use to search short substrings in short texts? By short I mean 5-10 characters for substring and 255 for the string. I'm thinking about choosing algorithm depending on input data length. Which algorithm is better for longer inputs? ...
Hello, I'm facing a parameter selection problem, which I would like to solve using Genetic Algorithm (GA). I'm supposed to select not more than 4 parameters out of 3000 possible ones. Using the binary chromosome representation seems like a natural choice. The evaluation function punishes too many "selected" attributes and if the number o...
I need to estimate a complexity of words for typists. For example "suffer" is easy than "people" becouse "o" and "p" is harder than "e" and "r". Any key pressed by little finger is more hard to hit than by index finger. And move finger from basic position is more harder than do not move. And use shift key also add hardness. What approa...
How can I tell if a point belongs to a certain line? Examples are appreciated, if possible. ...
I guess this is a simple question. I need to do something like this: std::set<int> s1, s2; s1 = getAnExcitingSet(); transform(s1.begin(), s1.end(), std::back_inserter(s2), ExcitingUnaryFunctor()); Of course, back_inserter doesn't work since there's no push_back. std::inserter also needs an iterator? I haven't used inserter so I'm not ...
This is applicable to Google App Engine, but not necessarily constrained for it. On Google App Engine, the database isn't relational, so no aggregate functions (such as sum, average etc) can be implemented. Each row is independent of each other. To calculate sum and average, the app simply has to amortize its calculation by recalculatin...
Hi all, I have big square. And I would like to split this square into small squares. I need all possible combinations. I know that there are infinity count of combinations but I have one limitation. I have fixed size for smallest square. I can implement it using brute force. But it is too long. Is any preferable algorithm for this tas...
I'm a web-game developer and I got a problem with random numbers. Let's say that a player has 20% chance to get a critical hit with his sword. That means, 1 out of 5 hits should be critical. The problem is I got very bad real life results -- sometimes players get 3 crits in 5 hits, sometimes none in 15 hits. Battles are rather short (3-1...