We want to search for a given element in a circular sorted array in complexity not greater than O(Log n). ex: search for 13 in {5,9,13,1,3}. My idea was to convert the circular array into a regular sorted array then do a binary search on the resulting array, but my problem was the algorithm i came up was stupid that it takes O(n) in the ...
I'm trying to learn more about trust metrics (including related algorithms) and how user voting, ranking and rating systems can be wired to stiffle abuse. I've read abstract articles and papers describing trust metrics but haven't seen any actual implementations. My goal is to create a system that allows users to vote on other users and ...
Hello, everyone! I am implementing a text-based version of Scrabble for a college project. I have a vector containing around 400K strings (my dictionary), and, at some point in every turn, I'm going to have to check if there's still a word in the dictionary which can be formed with the pieces in the player's hand. I'm checking if the p...
I need to "blindly" (i.e. without access to the filesystem, in this case the source control server) convert some relative paths to absolute paths. So I'm playing with dotdots and indices. For those that are curious I have a log file produced by someone else's tool that sometimes outputs relative paths, and for performance reasons I don't...
Suppose we have the following method (it is in c code): const char *bitap_search(const char *text, const char *pattern) My question is how can I compare text and pattern if they are char? This method is like a substring problem but I am confused a bit can I write in term of char such code? if (text[i]==pattern[i])? look i am interesti...
I need to count the quantiles for a large set of data. Let's assume we can get the data only through some portions (i.e. one row of a large matrix). To count the Q3 quantile one need to get all the portions of the data and store it somewhere, then sort it and count the quantile: List<double> allData = new List<double>(); foreach(var ro...
http://en.wikipedia.org/wiki/All_nearest_smaller_values. This is the site of the problem and here is my code, but I have some trouble to implement it: import java.util.*; public class stack{ public static void main(String[]args){ int x[]=new int[]{ 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 }; Stack<Int...
I need a collection data-structure that can do the following: Be sorted Allow me to quickly pop values off the front and back of the list O(log n) Remain sorted after I insert a new value Allow a user-specified comparison function, as I will be storing tuples and want to sort on a particular value Thread-safety is not required Optiona...
Suppose code is given like this: pattern_mask[pattern[i]] &= ~(1UL << i); What kind of type is this in Java? How do I implement this in Java? ...
Hi all, I was wondering if there is an algorithm to split a line into multiple lines, so that the resulting set of multiple lines fit into a squared shape rather than a wide rectangular shape. Let me give some examples, Input: Hi this is a really long line. Output: Hi this is a really long line Input: a b c d e f Output: a b c d e...
Hi, I have to search a 25 GB corpus of wikipedia for a single word. I used grep but it takes lot of time. Is there a efficient and easy representation that can be made to search quickly. Also, I want to find exact match. Thank you. ...
Hello, Say I have 50 million features, each feature comes from disk. At the beggining of my program, I handle each feature and depending on some conditions, I apply some modifications to some. A this point in my program, I am reading a feature from disk, processing it, and writing it back, because well I don't have enough ram to open ...
If I have a 2D array that is arranged as follows : String X[][] = new String [][] {{"127.0.0.9", "60", "75000","UDP", "Good"}, {"127.0.0.8", "75", "75000","TCP", "Bad"}, {"127.0.0.9", "75", "70000","UDP", "Good"}, {"127.0.0.1", "", "70000","UDP", "Good"}, ...
I'm stuck with some problem where I have to design a leader election algorithm for an oriented hypercube. This should be done by using a tournament with a number of rounds equal to the dimension D of the hypercube. In each stage d, with 1 <= d < D two candidate leaders of neighbouring d-dimensional hypercubes should compete to become the...
This is an array of objects showing a user uploading photos: Array ( [12] => stdClass Object ( [type] => photo [created] => 2010-05-14 23:36:41 [user] => stdClass Object ( [id] => 760 [username] => mrsmith ) ...
From programming pearls, it is known that array[1...n] has heap property if for all 2<=i<=n x[i/2]<=x[i]. Here is my code: import java.math.*; public class Heap { public static void main(String[]args) { int x[]=new int[]{12,20,15,29,23,17,22,35,40,26,51,19}; for (int i=2;i<x.length;i++) { ...
NOTE: This is a challenging problem for anybody who likes logic problems, etc. Consider a rectangular two-dimensional grid of height H and width W. Every space on the grid has a value, either 0 1 or 2. Initially, every space on the grid is a 0, except for the spaces along each of the four edges, which are initially a 2. Then consider a...
I am operating on a (not so) large graph having about 380K edges. I wrote a program to count the number of 3-cliques in the graph. A quick example: List of edges: A - B B - C C - A C - D List of cliques: A - B - C MySQL Table structure: +-------+------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default...
I need to generate encoding String for each item I inserted into the database. for example: x00001 for the first item x00002 for the sencond item x00003 for the third item The way I chose to do this is counting the rows. Before I insert the third item, I count against the database, I know there're already 2 rows, so the next encoding ...
Dear ladies and sirs. I need to convert an array of bytes to another base, namely 85. In math terms the question is how to convert from base-256 to base-85 in the most efficient way? This question is inspired by my previous question - http://stackoverflow.com/questions/2827627/what-is-the-most-efficient-way-to-encode-an-arbitrary-guid-...