Search Results

Search found 17940 results on 718 pages for 'algorithm design'.

Page 230/718 | < Previous Page | 226 227 228 229 230 231 232 233 234 235 236 237  | Next Page >

• What are the advantages of a rebase over a merge in git?

  - by eSKay

  In this article, the author explains rebasing with this diagram: Rebase: If you have not yet published your branch, or have clearly communicated that others should not base their work on it, you have an alternative. You can rebase your branch, where instead of merging, your commit is replaced by another commit with a different parent, and your branch is moved there. while a normal merge would have looked like this: So, if you rebase, you are just losing a history state (which would be garbage collected sometime in the future). So, why would someone want to do a rebase at all? What am I missing here?

  Read the article

• Efficient Array Storage for Binary Tree

  - by Sundararajan S

  We have to write the nodes of a binary tree to a file. What is the most space efficient way of writing a binary tree . We can store it in array format with parent in position 'i' and its childs in 2i,2i+1. But this will waste lot of space in case of sparse binary trees.

  Read the article

• Fast, Vectorizable method of taking floating point number modulus of special primes?

  - by caffiend

  Is there a fast method for taking the modulus of a floating point number? With integers, there are tricks for Mersenne primes, so that its possible to calculate y = x MOD 2^31 without needing division. Can any similar tricks be applied for floating point numbers? Preferably, in a way that can be converted into vector/SIMD operations, or moved into GPGPU code. The primes I'm interested in would be 2^7 and 2^31, although if there are more efficient ones for floating point numbers, those would be welcome.

  Read the article

• Best practices and Design Patterns for iPhone forms?

  - by cannyboy

  Part of the app I'm making requires the user to fill in a multi-page form, the contents of which will be saved locally (perhaps using Core Data). Are there any best practices for this? This form just includes text fields. I guess the options are UITextFields, or perhaps a UIWebView, with the fields as part of an html form? Are there are any best practices, or design patterns, which are good for this kind of thing?

  Read the article

• Given a few strings, how many strings can be lexicographically least by modifying the alphabet?

  - by Jackson W

  Number of strings can be huge as in 30000. Given N strings, output which ones can be lexicographically least after modifying the english alphabet. e.g. acdbe...... for example if the strings were: omm moo mom ommnom "mom" is already lexicographically least with the original english alphabet. we can make the word "omm" least by switching "m" and "o" in the alphabet ("abcdefghijklonmpqrstuvwxyz"). the other ones you cant make lexicographically last, no matter what you do. any fast way to do this? I have no ways to approach this except try every single possible alphabet

  Read the article

• Generate encoding String according to creation order.

  - by Tony

  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 is ended with 3. But there is a problem. If I delete the second item, the forth item will not be the x00004,but x00003. I can add additional columns to table, to store the next encoding, I don't know if there's other better solutions ?

  Read the article

• .NET Performance: Deep Recursion vs Queue

  - by JeffN825

  I'm writing a component that needs to walk large object graphs, sometimes 20-30 levels deep. What is the most performant way of walking the graph? A. Enqueueing "steps" so as to avoid deep recursion or B. A DFS (depth first search) which may step many levels deep and have a "deep" stack trace at times. I guess the question I'm asking is: Is there a performance hit in .NET for doing a DFS that causes a "deep" stack trace? If so, what is the hit? And would I better better off with some BFS by means of queueing up steps that would have been handled recursively in a DFS? Sorry if I'm being unclear. Thanks.

  Read the article

• Determining The Coordinates Of A Point Based On Its Known Difference From Three Other Points

  - by Joshua

  I have the coordinates of three points on a plane. Let's call them X1,Y1, X2,Y2, X3 Y3. I need to calculate X4,Y4 but all I know is: X1,Y1 is 350 units in distance from X4,Y4 X2,Y2 is 200 units in distance from X4,Y4 X3,Y3 is 50 units in distance from X4,Y4 I Know The Exact Values For X1,Y1, X2,Y2, and X3,Y3 How can I determine the exact location of X4,Y4?

  Read the article

• How can I store this kind of graph in neo4j for fast traversal?

  - by James

  This is a graph whose nodes exist in many connected components at once because a node's relationships are a collection of edge groups such that only one edge per edge group can be present at once. I need to be able to find all of the connected components that a node exists in. What would be the best way to store this graph in neo4j to quickly find all of the connected components that a node exists in? Is there a way to use the built in traversals to do this? Also: is there a name for this kind of graph? I'd appreciate any help/ideas. Update: Sorry for not being clear. All nodes are of the same type. Nodes have a variable number of edge groups. Exactly one edge from each edge group needs to be chosen for a particular connected component. I'm going to try to explain through example: Node x1 is related to: (x2 or x3 or x4) AND (x5 or x6) AND (x7) Node x2 is related to: (x8) AND (x9 or x10) So x1's first edge group is (x2, x3, x4), its second edge group is (x5, x6), and its third edge group is (x7). So here are a few connected components that x1 exists in: CC1: x1 is related to: x2, x5, x7 x2 is related to: x8 x9 CC2: x1 is related to: x2, x6, x7 x2 is related to: x8, x9 CC3: x1 is related to: x3, x5, x7 CC4: x1 is related to: x3, x6, x7 etc. I'm grateful for your help in this.

  Read the article

• parsing of mathematical expressions

  - by gcc

  (in c90) (linux) input: sqrt(2 - sin(3*A/B)^2.5) + 0.5*(C*~(D) + 3.11 +B) a b /*there are values for a,b,c,d */ c d input: cos(2 - asin(3*A/B)^2.5) +cos(0.5*(C*~(D)) + 3.11 +B) a b /*there are values for a,b,c,d */ c d input: sqrt(2 - sin(3*A/B)^2.5)/(0.5*(C*~(D)) + sin(3.11) +ln(B)) /*max lenght of formula is 250 characters*/ a b /*there are values for a,b,c,d */ c /*each variable with set of floating numbers*/ d As you can see infix formula in the input depends on user. My program will take a formula and n-tuples value. Then it calculate the results for each value of a,b,c and d. If you wonder I am saying ;outcome of program is graph. /sometimes,I think i will take input and store in string. then another idea is arise " I should store formula in the struct" but i don't know how I can construct the code on the base of structure./ really, I don't know way how to store the formula in program code so that I can do my job. can you show me? /* a,b,c,d is letters cos,sin,sqrt,ln is function*/

  Read the article

• Data Structures for hashMap, List and Set

  - by harigm

  Can any one please guide me to look in depth about the Data Structures used and how is it implemented in the List, Set and Maps of Util Collection page. In Interviews most of the questions will be on the Algorithms, but I never saw anywhere the implementation details, Can any one please share the information.

  Read the article

• Make function non-recursive

  - by user69514

  I'm not sure how to make this function non-recursive. Any ideas?: void foo(int a, int b){ while( a < len && arr[a][b] != -1){ if(++a == len){ a = 0; b++; } } if( a == len){ size++; return; } if( a < (len-1)){ arr[a][b] = 1; arr[a][(b+1)] = 1; foo(a, b); arr[a][b] = -1; arr[a][(b+1)] = -1; } if( a < (len-1) && arr[(a+1)][b] == -1){ arr[a][b] = 0; arr[(a+1)][b] = 0; foo(a,b); arr[a][b] = -1; arr[(a+1)][b] = -1; } }

  Read the article

• Sort months ( with strings ) algorithm

  - by Oscar Reyes

  I have this months array: ["January", "March", "December" , "October" ] And I want to have it sorted like this: ["January", "March", "October", "December" ] I'm currently thinking in a "if/else" horrible cascade but I wonder if there is some other way to do this. The bad part is that I need to do this only with "string" ( that is, without using Date object or anything like that ) What would be a good approach?

  Read the article

• Need help understanding this MATLAB function implementation

  - by Runner

  http://www.cc.gatech.edu/classes/AY2000/cs7495_fall/participants/sashag/ps3/getchaincode.m offset = N/2; %offset between ajacent pixels I don't understand what the above mean?

  Read the article

• How to implement Unary coding?

  - by davit-datuashvili

  How to impelement Unary encoding? For example how can we differ n (non-negative) from n (strictly positive)? I don’t understand a bit. Please help me.

  Read the article

• How to find validity of a string of parentheses, curly brackets and square brackets?

  - by Rajendra

  I recently came in contact with this interesting problem. You are given a string containing just the characters '(', ')', '{', '}', '[' and ']', for example, "[{()}]", you need to write a function which will check validity of such an input string, function may be like this: bool isValid(char* s); these brackets have to close in the correct order, for example "()" and "()[]{}" are all valid but "(]", "([)]" and "{{{{" are not! I came out with following O(n) time and O(n) space complexity solution, which works fine: Maintain a stack of characters. Whenever you find opening braces '(', '{' OR '[' push it on the stack. Whenever you find closing braces ')', '}' OR ']' , check if top of stack is corresponding opening bracket, if yes, then pop the stack, else break the loop and return false. Repeat steps 2 - 3 until end of the string. This works, but can we optimize it for space, may be constant extra space, I understand that time complexity cannot be less than O(n) as we have to look at every character. So my question is can we solve this problem in O(1) space?

  Read the article

• Parsing a comma-separated list

  - by alex

  I have a comma-separated list of values, for example: strins s = "param1=true;param2=4;param3=2.0f;param4=sometext;"; I need a functions: public bool ExtractBool(string parameterName, string @params); public int ExtractInt(string parameterName, string @params); public float ExtractFloat(string parameterName, string @params); public string ExtractString(string parameterName, string @params); Is there a special functions in .net that can help me with csl ? PS: parameter names are equal within a list.

  Read the article

• Result of Long Positive Integers & Search and element in array..

  - by AGeek

  Hi, I have two Questions for which I cannot find answers by googling, but I find these questions very important for preparation.. Kindly explain only the logic, I will be able to code. In Search of Efficient Logic..... in terms of Memory and Time. WAP to add two long positive integers. What Data structure / data type we can use to store the numbers and result. What is the best way to search an element from an array in shortest time. Size of the array could be large enough, and any elements could be stored in the array(i.e. no range). Thanks.

  Read the article

• An O(1) Sort ~~~

  - by FlySwat

  Before you stone me for being a heretic, There is a sort that proclaims to be O(1), called "Bead Sort" (http://en.wikipedia.org/wiki/Bead_sort) , however that is pure theory, when actually applied I found that it was actually O(N * M), which is pretty pathetic. That said, Lets list out some of the fastest sorts, and their best case and worst case speed in Big O notation. ~~ FlySwat ~~

  Read the article

• Efficient way to get highly correlated pairs from large data set in Python or R

  - by Akavall

  I have a large data set (Let's say 10,000 variables with about 1000 elements each), we can think of it as 2D list, something like: [[variable_1], [variable_2], ............ [variable_n] ] I want to extract highly correlated variable pairs from that data. I want "highly correlated" to be a parameter that I can choose. I don't need all pairs to be extracted, and I don't necessarily want the most correlated pairs. As long as there is an efficient method that gets me highly correlated pairs I am happy. Also, it would be nice if a variable does not show up in more than one pair. Although this might not be crucial. Of course, there is a brute force way to finding such pairs, but it is too slow for me. I've googled around for a bit and found some theoretical work on this issue, but I wasn't able for find a package that could do what I am looking for. I mostly work in python, so a package in python would be most helpful, but if there exists a package in R that does what I am looking for it will be great. Does anyone know of a package that does the above in Python or R? Or any other ideas? Thank You in Advance

  Read the article

• How much time should it take to find the sum of all prime numbers less than 2 million?

  - by Shahensha

  I was trying to solve this Project Euler Question. I implemented the sieve of euler as a helper class in java. It works pretty well for the small numbers. But when I input 2 million as the limit it doesn't return the answer. I use Netbeans IDE. I waited for a lot many hours once, but it still didn't print the answer. When I stopped running the code, it gave the following result Java Result: 2147483647 BUILD SUCCESSFUL (total time: 2,097 minutes 43 seconds) This answer is incorrect. Even after waiting for so much time, this isn't correct. While the same code returns correct answers for smaller limits. Sieve of euler has a very simple algo given at the botton of this page. My implementation is this: package support; import java.util.ArrayList; import java.util.List; /** * * @author admin */ public class SieveOfEuler { int upperLimit; List<Integer> primeNumbers; public SieveOfEuler(int upperLimit){ this.upperLimit = upperLimit; primeNumbers = new ArrayList<Integer>(); for(int i = 2 ; i <= upperLimit ; i++) primeNumbers.add(i); generatePrimes(); } private void generatePrimes(){ int currentPrimeIndex = 0; int currentPrime = 2; while(currentPrime <= Math.sqrt(upperLimit)){ ArrayList<Integer> toBeRemoved = new ArrayList<Integer>(); for(int i = currentPrimeIndex ; i < primeNumbers.size() ; i++){ int multiplier = primeNumbers.get(i); toBeRemoved.add(currentPrime * multiplier); } for(Integer i : toBeRemoved){ primeNumbers.remove(i); } currentPrimeIndex++; currentPrime = primeNumbers.get(currentPrimeIndex); } } public List getPrimes(){ return primeNumbers; } public void displayPrimes(){ for(double i : primeNumbers) System.out.println(i); } } I am perplexed! My questions is 1) Why is it taking so much time? Is there something wrong in what I am doing? Please suggest ways for improving my coding style, if you find something wrong.

  Read the article

• Can my tortoise vs. hare race be improved?

  - by FredOverflow

  Here is my code for detecting cycles in a linked list: do { hare = hare.next(); if (hare == back) return; hare = hare.next(); if (hare == back) return; tortoise = tortoise.next(); } while (tortoise != hare); throw new AssertionError("cyclic linkage"); Is there a way to get rid of the code duplication inside the loop? Am I right in assuming that I don't need a check after making the tortoise take a step forward? As I see it, the tortoise can never reach the end of the list before the hare (contrary to the fable). Any other ways to simplify/beautify this code?

  Read the article

• how to Design a vista like button using CSS

  - by GayaMani

  can any one tell me the way to design vista like buttons using CSS for the application in ASP.NET. For the Buttons like Save,delete,Cancel etc

  Read the article

• Quick way to do data lookup in PHP

  - by Ghostrider

  I have a data table with 600,000 records that is around 25 megabytes large. It is indexed by a 4 byte key. Is there a way to find a row in such dataset quickly with PHP without resorting to MySQL? The website in question is mostly static with minor PHP code and no database dependencies and therefore fast. I would like to add this data without having to use MySQL if possible. In C++ I would memory map the file and do a binary search in it. Is there a way to do something similar in PHP?

  Read the article

• Find the centroid of a polygon with weighted vertices

  - by Calle Kabo

  Hi, I know how to find the centroid (center of mass) of a regular polygon. This assumes that every part of the polygon weighs the same. But how do I calculate the centroid of a weightless polygon (made from aerogel perhaps :), where each vertex has a weight? Simplified illustration of what I mean using straight line: 5kg-----------------5kg ^center of gravity 10kg---------------5kg ^center of gravity offset du to weight of vertices Of course, I know how to calculate the center of gravity on a straight line with weighted vertices, but how do I do it on a polygon with weighted vertices? Thanks for your time!

  Read the article

< Previous Page | 226 227 228 229 230 231 232 233 234 235 236 237  | Next Page >