I was just wondering how the Arrays.sort() method is so fast. I created my own algorithm and ran it against quicksort and I was happy with the results, but then to make sure I was actually sorting the method correctly I used Arrays.sort() and Arrays.equals() and it finished too fast. My ...

Hi, I want to parse (math) expressions. I searched the forum and googled, but i didn't found any (possitive :)) help. What i need is to locate the first substring with a pair of parenthesis. I read that parenthesis matching cannot be done by "one" regex, since there is no way to "count" in ...

Hi every body;I just want any codes or website how can I read from a file and what is depth-first and breadth-first search strategiesplzzzzzzzzzzz it is very important if you can give me a site or a description about these codes^_^

i was given the following quick sort algoritm as part of project. We have to Analysis its performance against other sorting algoritms.it works fine for randomly sorted arrays.However when i run a reverse array i get a java.lang.StackOverflowError.I've heard this can be caused by infinite ...

I've beem fleshing out a data structure API to define and implement data structure type that java.util doesn't (such as graphs and trees), and I've been wondering: Is defining and implementing a search tree type worth it?I suppose my question really is: Is there anything I might to use a ...

Can anyone suggest an algorithm to sort an array into althernating male and female? e.g.Smith MSmith FTaylor MTaylor FThe algorithm needs to disturb the list as little as possible so other criteria can also be used e.g. test scores. Also, it can't be exact because there is rarely exactly 50% ...

I have a QuickSort algorithm and I have measured the performance of this algorithm by geting the number of comparisions and copies it performs for a number of array sizes. How can I work out what the complexity is for comparisions and copies?Thanks for the help.

hey ppl, i need an algorithm that can detect the best path to get in an array from a to b. however,shortest path is not what i need,since there might be a path that goes backwards.anyway i wanted to test the complexity of the algorithm first, and i got an error. however, i don't know if it can ...

I am quite new to Java and trying to find a way to use microphone and pass the data from microphone to a FFT Class and get the result back as one number (which will be the frequency). Because I am quite new, I am in need of some advice and description to solve this problem.I will be glad if ...

I'm trying to generate a string that represents a sum of products expression.Here are some examples of strings for various degrees:// degree = 2if (t >= knot[i] && t <= knot[i+1] && knot[i] != knot[i+1]) {d = a(i,k);}else if (t >= knot[i+1] && t <= knot[i+2] ...

Hi,Can someone explain the code in the folloiwng- I need a detailed explanationclass Stemmer{ private char[] b;private int i,/* offset into b */i_end, /* offset to end of stemmed word */j, k;private static final int INC = 50; /* unit of size whereby b is increased */public Stemmer(){ b = new ...

Is there a way (instead of going through all the numbers) to output the numbers with only a specified number of bits?For example, take the numbers 0-150000000100100011010001010110011110001001101010111100110111101111If the goal was to output the numbers with only 1 1-bit, then the outputted list ...

Hi, It is easy to see, that graph theory is of great interest for the majority of the Algorithms forum visitors. Since i am going to start writing a graph theory library and I will need help for sure in the near furure, I believe that it would be more helpful for all of us, to post our ...

i want to write MAJORITY ALGORITHM in both recursive as well as iterative manner.i tryed but i could not , can any one help me please.this is the algorithm:Algorithm MAJORITYInput An array A[100n] of n elementOutput The majorty element if it exist; otherwise none.1. c < candidate(1)2. count ...

I have a file in my porject.How or in which format or way I convert that file so someone can not readit or even if they read it wont make sense.But my code if reqd can read file content.

Hi-yaI would like to use a TreeBidiMap as implemented in apache commons - http://jakarta.apache.org/commons/collections/userguide.htmlThese represent maps where the the key can lookup the value and the value can lookup the key with equal ease.for example:BidiMap bidi = new ...

I have trouble finding derivative of logarithmic function:Supposed I have the following problem: Lim (as n --> infinity) 3(log n)^4 / 3nlog n + 2nHow do I find the limit of the above using l'hospital rule? I need to find the limit to determine the run time whether it is big_O, big_thete, or ...

Hi, everyone, i need some help here, some of my logic seems gone worng in my application. My program suppose to work as follow: firstly, i click as much circle as i like. After i press the connect button, if i click any of two circle, a line can be draw between their central point. and I want ...

Can someone point me to a link which implements the following conflation algorithms in Java-1. n-gram2. successor variety3. table lookup

Im doing a project about different security alogrithms, and they are coded in java. I cant seem to find any version of knapsack coded in java on the web, can anyone help, or tell me where I could view source code for this?

I'm trying to replace all backslashes in a string with double backslashes... but am getting some errors during runtime.Here's what I'm using:str = str.replaceAll("\\\\", "\\\\\\");Here's the error I'm getting during runtime:java.lang.StringIndexOutOfBoundsException: String index out of ...

I want to access DB from Strutus framework, Pl. suggest the best approach

k = 0for i = 1 to n dofor j = n down to i dok = k + 1if j < 8 thenk = k + jI am practicing analyzing worse case for algorithms and run across this interesting algorithm (at least interesting to me). What is the runtime of the above algorithm? I think it's N^2 but I am not so sure - looks ...

Please have a look at this problem...Thank you..(the problem is ok with one traveler. but when two or more come into the picture they really mess things up)Here it isI have a number of destinations that devides evenly up between anumber of travelers. (5 travelers with 20 destinations = ...

Hello,I'm trying this program out of self interest. I would like inputs regding where i can start off...My Reqmt is this:..If i have 10 nos... 1,2 3,4,5,6,..10...Everytime i run my program it should generate a different combination of numbers 4 2 5 8 3 ...covering all 10 nos.next time 5 7 3 9 ...

Hey, I'm working on a simple Java calculator and I am looking for some asstance.It's a fairly simple system.I have two stacks containing two different Object types. I have Double and Operator, both are wrapper classes. Doubles are operands while Operators are, well, operators.The program will ...

I'm working on an applet that is required to expand a polynomial with up to four variables. I've written two things that work well for small cases, but both were unable to handle larger cases with all four variables. Here's the largest ...

do you have a good algorithm to reverse a linkedlist, that is, the second node points to the first node, the third one points to the second, as so on?

Sorry... if there was enough space ot would say..."What is the minimum set of data required to extract three 2D arrays from a single string of values?"In particular when these arrays are designed and used for matracies caluculations.More specificaly when these matrices represnt the connections ...

Hello,I am trying to write a java method which takes a hashmap as the input. The hashmap looks as follows:Key Value**** ******Q1 V11,V12,V13,V14....V1n (This is a collection)Q2 V21,V22,V23,V24....V2n (This is a collection)....Qm Vm1,Vm2,Vm3,Vm4....Vmn (This is a collection)The method should ...

Hi all,I need to transform a list of numbers in binary digits and then I must find the way to analyze each bit, so that "0" gives me something and "1" gives me something else.For example: 6 --> 110. First I analyze "1", then the other "1" and last the "0" in recursive way. I hope I've been ...

HI there,I am trying to write a method that would allow me to test a combination of a given number of variables, to check whether it satisfies some conditions. I have come to a conclusion that, depending on the total number of variables, I will have to write as many for loops each time the # of ...

Hi. I have a requirement to sort the HashMap based on the values not on the keys. My HashMap contains the values which are duplicates. My program is some thing like this.Map m = new HashMap();m.put ("Gosling", new Integer(2000));m.put ("Joy", new Integer(2000));m.put ("Schwartz", new ...

i'm trying to write a text editor for any programming language but i'm having a problem with highlighting the keywords. I can highlight the actual keywords easily but i cant stop it highlighting keywords within other words. for example:System.out.println("Hello World"); Not sure how to solve ...

i'm a newbie in Java programming. I wanted to know how do i write an algorithm for sql in java. Can anyone please help me or provide me with some useful tutorials and link that i can follow thru..Thank you.

Can anyone give me a clear idea as to how do I perform an Image Matching between a source Image and the target Image(source Image rotated to right or left ) . I mean if i have the exact same Image i get the best match with my current algorithm .But if the Image is rotated how do I get the ...

can anyone suggest an algorithm to find all unique paths between two nodes?I have already implemented a variation of Dijkstra's shortest path algorithm to find ONE path, i'm just not sure how I can find ALL unique paths..Any help much appreciated.thanks :)

Hi all,Does anyone have any idea about which algorithm is most appropriate to search for items/events in a data stream of logs? Regards,mas

Hi,I am facing a "little" problem and I hope you could help me.I'll try to formulate it clearly.I have a set of items (to be distributed in containers) and I I have define how muchcontainers I need to contain all these items.Each item is characterised by two values that are used to check ...

I've been working on generating mazes using a variety of techniques. I have successfully implemented the DFS and Prim's algorithm. I'm currently encountering difficulty implementing Kruskal's algorithm. This is mostly due to my lack of understanding pertaining to union-find algorithms. ...

hi! is there anyone who could help us in chossing the right path planning algorithm to our project. the project should work this way...but first let me tell you that we have a mobile robot and a number of flowerpots contained in an area which is approximately 5 feet by 5 feet. Prior to the main ...

Hey all mathematicians...I need to figure out a way to print all the possible permutations of a given string in java. I uderstand this would use recursion. I would like the program to use any possible string with any length of string. But even if it would work for only 4 characters consisting ...

In reference to this thread: http://forum.java.sun.com/thread.jspa?forumID=426&threadID=435407around reply 20 I mentioned a Graph API but never gave a URL whereit can be accessed, mainly because it wasn't ready.Well, it has just been released as part of a demo application calledGart Demo, ...

Hi,Does anyone know of Java code/library that given a tree structure will enumerate all the possible subtrees. Ideally the tree should be represented as a set of linked nodes similary to the way JTrees can be built using DefaultMutableTreeNode. I've tried doing a exhaustive algorithm to get ...

Is there a Wavelet transform libraray for Images in Java. I feel there should be some wavelet class for (Haar, Daub , Fourier and such transforms). If some one could give me pointers that would be great. Thanks in Advance.

Hi Everyone,I was working on a permutation algorithm (don't know if it already exists). The purpose of this algortihm is to be parallel so I can set it up on a grid. Here is the idea:I recieve an string s of a size l. Then, i fragment the string so i create a list of small goups that al ...

Having trouble with my minmax algorithm for my game. Keep getting StackOverFlowError - possible due to too much recursion? If it is too much recusion - ie the game tree is too vast what should I do?This is just for a Dominoes game - so I didnt think it would be that complicated :SAny help / ...

Hi everyone,-I need to create a function that will take a string of 1's and 0's. -The string length will be from 1 to 8, if the length of the string is below 8, it will add trailing 0's (to make 8 bits)ie. packStrToByte("1011") would return 176 (10110000)I want to pack that string in a byte ...

Hi everyone :)I want to know how can i calculate statistical figures....namely, mode(frequency) through java...i take values(results) from a vector.....?Can anyone pls help?

Hi folks!I've planed to write a new "database explorer" firtly I mean to use this project in my Java Developer Certification Exams, after(or before) I want to open the source and have another database explorer in the open source world. :)My firts ideas are around a different way to implement ...