Search Results

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

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 239/718 | < Previous Page | 235 236 237 238 239 240 241 242 243 244 245 246  | Next Page >

  • R implementation of sorting by reversals

    - by user1357015
    I was wondering if there is an implementation in R where it sorts a permutation of n numbers into the original 1...n sequence and provides the number of reversals needed. Eg an implementation of the "sorting by reversals" or "sorting by translocation" as outlined in this ppt. Specifically, I have a permutation of a sequence of n elements, pi(n), and I want to figure out how close it is to the original sequence. The number of reversals seems a good metric. Thanks!

    Read the article

  • How to read arbitrary number of values using std::copy?

    - by Miro Kropacek
    Hi, I'm trying to code opposite action to this: std::ostream outs; // properly initialized of course std::set<int> my_set; // ditto outs << my_set.size(); std::copy( my_set.begin(), my_set.end(), std::ostream_iterator<int>( outs ) ); it should be something like this: std::istream ins; std::set<int>::size_type size; ins >> size; std::copy( std::istream_iterator<int>( ins ), std::istream_iterator<int>( ins ) ???, std::inserter( my_set, my_set.end() ) ); But I'm stuck with the 'end' iterator -- input interators can't use std::advance and neither I can use two streams with the same source... Is there any elegant way how to solve this? Of course I can use for loop, but maybe there's something nicer :)

    Read the article

  • How to optimize this simple function which translates input bits into words?

    - by psihodelia
    I have written a function which reads an input buffer of bytes and produces an output buffer of words where every word can be either 0x0081 for each ON bit of the input buffer or 0x007F for each OFF bit. The length of the input buffer is given. Both arrays have enough physical place. I also have about 2Kbyte free RAM which I can use for lookup tables or so. Now, I found that this function is my bottleneck in a real time application. It will be called very frequently. Can you please suggest a way how to optimize this function? I see one possibility could be to use only one buffer and do in-place substitution. void inline BitsToWords(int8 *pc_BufIn, int16 *pw_BufOut, int32 BufInLen) { int32 i,j,z=0; for(i=0; i<BufInLen; i++) { for(j=0; j<8; j++, z++) { pw_BufOut[z] = ( ((pc_BufIn[i] >> (7-j))&0x01) == 1? 0x0081: 0x007f ); } } } Please do not offer any compiler specific or CPU/Hardware specific optimization, because it is a multi-platform project.

    Read the article

  • Reduce text length to fit cell width in a smart manner

    - by Andrei Ciobanu
    Hello, I am in project where we are building a simple web calendar using Java EE technologies. We define a table where every row is an employee, and every column represents an hour interval. The table width and column widths are adjustable. In every cell we have a text retrieved from a database, indicating what the employee is doing / should do in that time interval. The problem is that sometimes the text in cells is getting bigger than the actual cell. My task is to make the text more "readable" by reducing it's length in a "smart way" so that it can fit in the cell more "gracefully". For example if initially in a cell I have: "Writing documents", after the resize I should retrieve: "Wrtng. dcmnts" or "Writ. docum." so that the text can fit well. Is there a smart way to do it ? Or removing vocals / split the string in two is enough ?

    Read the article

  • Finding whether a point lies inside a rectangle or not

    - by avd
    The rectangle can be oriented in any way...need not be axis aligned. Now I want to find whether a point lies inside the rectangle or not. One method I could think of was to rotate the rectangle and point coordinates to make the rectangle axis aligned and then by simply testing the coordinates of point whether they lies within that of rectangle's or not. The above method requires rotation and hence floating point operations. Is there any other efficient way to do this??

    Read the article

  • question about in -place sort

    - by davit-datuashvili
    for example we have following array char data[]=new char[]{'A','S','O','R','T','I','N','G','E','X','A','M','P','L','E'}; and index array int a[]=new int[]{0,1,2,3,4,5,6,7,8,9,10,11,12,13,14}: void insitu(char data[],int a[],N){ for (int i=0;i<N;i++) { char v=data[i]; int j,int k; for (k=i;a[k]!=i;k=a[j];a[j]=j) { j=k;data[k]=data[a[k]; } data[k]=v; a[k]=k; } i have question what is initialize value of j? when i run this code it asks me to initialize j and what should do? }

    Read the article

  • How can we find second maximum from array efficiently?

    - by Xinus
    Is it possible to find the second maximum number from an array of integers by traversing the array only once? As an example, I have a array of five integers from which I want to find second maximum number. Here is an attempt I gave in the interview: #define MIN -1 int main() { int max=MIN,second_max=MIN; int arr[6]={0,1,2,3,4,5}; for(int i=0;i<5;i++){ cout<<"::"<<arr[i]; } for(int i=0;i<5;i++){ if(arr[i]>max){ second_max=max; max=arr[i]; } } cout<<endl<<"Second Max:"<<second_max; int i; cin>>i; return 0; } The interviewer, however, came up with the test case int arr[6]={5,4,3,2,1,0};, which prevents it from going to the if condition the second time. I said to the interviewer that the only way would be to parse the array two times (two for loops). Does anybody have a better solution?

    Read the article

  • phrase split algorithm in PHP

    - by Eric Sim
    Not sure how to explain. Let's use an example. Say I want to split the sentence "Today is a great day." into today today is today is a today is a great today is a great day is is a is a great is a great day a a great a great day great great day day The idea is to get all the sequential combination in a sentence. I have been thinking what's the best way to do it in PHP. Any idea is welcome.

    Read the article

  • how to find out if a shape is passable

    - by jd
    I have a complex polygon (possibly concave) and a few of its edges marked as entry/exit points. there is a possibility that inside this polygon may lie one or more blockades of arbitrary shape. what approaches could I use to determine whether a path of certain width exists between a pair of entry/exit edges? having read through the question it looks like a homework type - it is not. I just wish to have a at least a few leads I could pursue, as this is new to me.

    Read the article

  • Finding the longest road in a Settlers of Catan game algorithmically

    - by Jay
    I'm writing a Settlers of Catan clone for a class. One of the extra credit features is automatically determining which player has the longest road. I've thought about it, and it seems like some slight variation on depth-first search could work, but I'm having trouble figuring out what to do with cycle detection, how to handle the joining of a player's two initial road networks, and a few other minutiae. How could I do this algorithmically? For those unfamiliar with the game, I'll try to describe the problem concisely and abstractly: I need to find the longest possible path in an undirected cyclic graph.

    Read the article

  • question about Batcher odd-even sort

    - by davit-datuashvili
    hi i ave question about Batcher's odd-even sort i have following code public class Batcher{ public static void batchsort(int a[],int l,int r){ int n=r-l+1; for (int p=1;p<n;p+=p) for (int k=p;k>0;k/=2) for (int j=k%p;j+k<n;j+=(k+k)) for (int i=0;i<n-j-k;i++) if ((j+i)/(p+p)==(j+i+k)/(p+p)) exch(a,l+j+i,l+j+i+k); } public static void main(String[]args){ int a[]=new int[]{2,4,3,4,6,5,3}; batchsort(a,0,a.length-1); for (int i=0;i<a.length;i++){ System.out.println(a[i]); } } public static void exch(int a[],int i,int j){ int t=a[i]; a[i]=a[j]; a[j]=t; } } //result is 3 3 4 4 5 2 6 what i missed ? hat is wrong?

    Read the article

  • How would I use for_each to delete every value in an STL map?

    - by stusmith
    Suppose I have a STL map where the values are pointers, and I want to delete them all. How would I represent the following code, but making use of std::for_each? I'm happy for solutions to use Boost. for( stdext::hash_map<int, Foo *>::iterator ir = myMap.begin(); ir != myMap.end(); ++ir ) { delete ir->second; // delete all the (Foo *) values. } (I've found Boost's checked_delete, but I'm not sure how to apply that to the pair<int, Foo *> that the iterator represents). (Also, for the purposes of this question, ignore the fact that storing raw pointers that need deleting in an STL container isn't very sensible).

    Read the article

  • Fast matrix transposition in Python

    - by psihodelia
    Is there any fast method to make a transposition of a rectangular 2D matrix in Python (non-involving any library import).? Say, if I have an array X=[[1,2,3], [4,5,6]] I need an array Y which should be a transposed version of X, so Y=[[1,4],[2,5],[3,6]].

    Read the article

  • Generate a valid array key from an URL string in PHP

    - by John Riche
    I have a PHP array with some predefined values: $aArray = array( 0 => 'value0', 1 => 'value1' ); I need to create a function where the string input will always return the same, valid, array key so that when I call: GiveMeAKey('http://www.google.com'); // May return 0 or 1 I receive always the same key (I don't care which one) from the array. Obvisously I can't store the relationship in a database and the string passed to the GiveMeAKey method can be any URL. I wonder if there is a way of doing that ?

    Read the article

  • Interview question: C program to sort a binary array in O(n)

    - by Zacky112
    I've comeup with the following program to do it, but it does not seem to work and goes into infinite loop. Its working is similar to quicksort. int main() { int arr[] = {1,1,0,1,0,0,0,1,0,1,0,1,0,1,0,1,0,1}; int N = 18; int *front, *last; front = arr; last = arr + N; while(front <= last) { while( (front < last) && (*front == 0) ) front++; while( (front < last) && (*last == 1) ) last--; if( front < last) { int temp = *front; *front = *last; *last = temp; front ++; last--; } } for(int i=0;i<N;i++) printf("%d ",arr[i]); return 0; }

    Read the article

  • How to convert from base-256 to base-N, where N is higher than 16?

    - by mark
    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-into-readable-ascii-3 Thanks.

    Read the article

  • Routing algorithm

    - by isaac
    Hello, I'm giving a presentation about computer routing and I want to make a good analogy with a real-world situation. However, I could not find it. Do you have in mind any of the situations like the computer routing. If yes, could you please provide me with it

    Read the article

  • Question about permute-by-sorting

    - by davit-datuashvili
    In the book "Introduction to Algorithms", second edition, there is the following problem: Suppose we have some array: int a[] = {1,2,3,4} and some random priorities array: P = {36,3,97,19} and the goal is to permute the array a randomly using this priorities array. This is the pseudo code: PERMUTE-BY-SORTING (A) 1 n ? length[A] 2 for i ? 1 to n 3 do P[i] = RANDOM (1, n 3) 4 sort A, using P as sort keys 5 return A The result should be the permuted array: B={2, 4, 1, 3}; I have written this code: import java.util.*; public class Permute { public static void main (String[] args) { Random r = new Random(); int a[] = new int[] {1,2,3,4}; int n = a.length; int b[] = new int[a.length]; int p[] = new int[a.length]; for (int i=0; i<p.length; i++) { p[i] = r.nextInt(n*n*n) + 1; } // for (int i=0;i<p.length;i++){ // System.out.println(p[i]); //} } } How do I continue?

    Read the article

  • Database design

    - by Hadad
    Hello, I've a system, that have two types of users (Companies and individuals).all types have a shared set of properties but they differ in another. What is the best design merge all in one table that allows null for unmatched properties, or separate them in two tables related to a basic table with a one to one relationship. Thanks.

    Read the article

  • Pointer mysteriously moves

    - by Armen Ablak
    Hi, I have this code for Node rotation and in a line which is marked something happens and I don't really know what and why :). //Test case 30 \ 16 / 29 RotationRight(node->mParent); //call template<class T> void SplayTree<T>::RotationRight(SplayNode<T> *&node) const { SplayNode<T> *left = node->mLeft; SplayNode<T> *parent = node->mParent; node->mLeft = left->mRight; if(left->HasRight()) left->mRight->mParent = node; left->mRight = node; //node in this line points to 0x00445198 {30} left->mParent = node->mParent; //and in this line it points to 0x00444fb8 {16} (node, not node->mParent) node->mParent = left; node = left; } Well, left-mParent points to node also, so I basically do node = node-mParent. The problem is I can't find a work around - how to unpin in from node and change it's pointing address without changing it's.

    Read the article

  • Triangulation in 3D Space

    - by w3b_wizzard
    Disclaimer: This is for class, however I'm fresh out of ideas and a nudge in the right direction would be much appreciated. Also, this needs to be implemented in raw C, so no fancy libraries can be used. I have to write a search and rescue simulator for submarines, it has to find a probe that is randomly placed in 3D space in a grid from of the MAX_XYZ (100000). The only tools I'm given are a "ping" which will give the magnitude of the distance between a certain sub and the probe. The goal is to optimize the costs of this entire operation so a brute force attempt, like looking at every single coordinate, won't work. Hence I was thinking triangulation. Now, it makes loads of sense to me, place three subs, each one of them uses their ping to get the distance between them and the probe. Since each sub have a known distance relative to one another, it's easy to build the base of a tetrahedron with them, and the results of the ping will point to a certain coordinate, the problem I'm having is how to figure out the elevation, or the height, of the tetrahedron. So what I have as data is the following: Distances between subs (In vector format) Angles between each subs (very easy to compute) Distance between each sub and the probe (3 segments from the base to the peak) Angles inside each of the outer 3 surfaces of the tetrahedron. I tried finding some sort of relationship with the vertices of the tetrahedron and the relative angles in each of them, however all I found had to deal with tetrahedrons built with equilateral triangles, which isn't much help. I have the impression this can be easily solved with trig but either I'm not seeing it or I need more coffee. Any suggestions would be appreciated!

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 235 236 237 238 239 240 241 242 243 244 245 246  | Next Page >