Search Results

Search found 17731 results on 710 pages for 'programming practices'.

Page 266/710 | < Previous Page | 262 263 264 265 266 267 268 269 270 271 272 273  | Next Page >

  • Derivative of a Higher-Order Function

    - by Claudiu
    This is in the context of Automatic Differentiation - what would such a system do with a function like map, or filter - or even one of the SKI Combinators? Example: I have the following function: def func(x): return sum(map(lambda a: a**x, range(20))) What would its derivative be? What will an AD system yield as a result? (This function is well-defined on real-number inputs).

    Read the article

  • How do languages handle side effects of compound operators?

    - by Kos
    Hello, Assume such situation: int a = (--t)*(t-2); int b = (t/=a)+t; In C and C++ this is undefined behaviour, as described here: Undefined Behavior and Sequence Points However, how does this situation look in: JavaScript, Java, PHP... C# well, any other language which has compound operators? I'm bugfixing a Javascript - C++ port right now in which this got unnoticed in many places. I'd like to know how other languages generally handle this... Leaving the order undefined is somehow specific to C and C++, isn't it?

    Read the article

  • How to declare a(n) vector/array of reducer objects in Cilk++?

    - by Jin
    Hi All, I had a problem when I am using Cilk++, an extension to C++ for parallel computing. I found that I can't declare a vector of reducer objects: typedef cilk::reducer_opadd<int> T_reducer; vector<T_reducer> bitmiss_vec; for (int i = 0; i < 24; ++i) { T_reducer r; bitmiss_vec.push_back(r); } However, when I compile the code with Cilk++, it complains at the push_back() line: cilk++ geneAttack.cilk -O1 -g -lcilkutil -o geneAttack /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h: In member function ‘void __gnu_cxx::new_allocator<_Tp>::construct(_Tp*, const _Tp&) [with _Tp = cilk::reducer_opadd<int>]’: /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_vector.h:601: instantiated from ‘void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = cilk::reducer_opadd<int>, _Alloc = std::allocator<cilk::reducer_opadd<int> >]’ geneAttack.cilk:667: instantiated from here /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h:229: error: ‘cilk::reducer_opadd<Type>::reducer_opadd(const cilk::reducer_opadd<Type>&) [with Type = int]’ is private /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/ext/new_allocator.h:107: error: within this context /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h: In member function ‘void std::vector<_Tp, _Alloc>::_M_insert_aux(__gnu_cxx::__normal_iterator<typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::pointer, std::vector<_Tp, _Alloc> >, const _Tp&) [with _Tp = cilk::reducer_opadd<int>, _Alloc = std::allocator<cilk::reducer_opadd<int> >]’: /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_vector.h:605: instantiated from ‘void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = cilk::reducer_opadd<int>, _Alloc = std::allocator<cilk::reducer_opadd<int> >]’ geneAttack.cilk:667: instantiated from here /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h:229: error: ‘cilk::reducer_opadd<Type>::reducer_opadd(const cilk::reducer_opadd<Type>&) [with Type = int]’ is private /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/vector.tcc:252: error: within this context /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_vector.h:605: instantiated from ‘void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = cilk::reducer_opadd<int>, _Alloc = std::allocator<cilk::reducer_opadd<int> >]’ geneAttack.cilk:667: instantiated from here /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h:230: error: ‘cilk::reducer_opadd<Type>& cilk::reducer_opadd<Type>::operator=(const cilk::reducer_opadd<Type>&) [with Type = int]’ is private /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/vector.tcc:256: error: within this context /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h: In static member function ‘static _BI2 std::__copy_backward<_BoolType, std::random_access_iterator_tag>::__copy_b(_BI1, _BI1, _BI2) [with _BI1 = cilk::reducer_opadd<int>*, _BI2 = cilk::reducer_opadd<int>*, bool _BoolType = false]’: /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_algobase.h:465: instantiated from ‘_BI2 std::__copy_backward_aux(_BI1, _BI1, _BI2) [with _BI1 = cilk::reducer_opadd<int>*, _BI2 = cilk::reducer_opadd<int>*]’ /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_algobase.h:474: instantiated from ‘static _BI2 std::__copy_backward_normal<<anonymous>, <anonymous> >::__copy_b_n(_BI1, _BI1, _BI2) [with _BI1 = cilk::reducer_opadd<int>*, _BI2 = cilk::reducer_opadd<int>*, bool <anonymous> = false, bool <anonymous> = false]’ /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_algobase.h:540: instantiated from ‘_BI2 std::copy_backward(_BI1, _BI1, _BI2) [with _BI1 = cilk::reducer_opadd<int>*, _BI2 = cilk::reducer_opadd<int>*]’ /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/vector.tcc:253: instantiated from ‘void std::vector<_Tp, _Alloc>::_M_insert_aux(__gnu_cxx::__normal_iterator<typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::pointer, std::vector<_Tp, _Alloc> >, const _Tp&) [with _Tp = cilk::reducer_opadd<int>, _Alloc = std::allocator<cilk::reducer_opadd<int> >]’ /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_vector.h:605: instantiated from ‘void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = cilk::reducer_opadd<int>, _Alloc = std::allocator<cilk::reducer_opadd<int> >]’ geneAttack.cilk:667: instantiated from here /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h:230: error: ‘cilk::reducer_opadd<Type>& cilk::reducer_opadd<Type>::operator=(const cilk::reducer_opadd<Type>&) [with Type = int]’ is private /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_algobase.h:433: error: within this context /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h: In function ‘void std::_Construct(_T1*, const _T2&) [with _T1 = cilk::reducer_opadd<int>, _T2 = cilk::reducer_opadd<int>]’: /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_uninitialized.h:87: instantiated from ‘_ForwardIterator std::__uninitialized_copy_aux(_InputIterator, _InputIterator, _ForwardIterator, std::__false_type) [with _InputIterator = cilk::reducer_opadd<int>*, _ForwardIterator = cilk::reducer_opadd<int>*]’ /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_uninitialized.h:114: instantiated from ‘_ForwardIterator std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = cilk::reducer_opadd<int>*, _ForwardIterator = cilk::reducer_opadd<int>*]’ /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_uninitialized.h:254: instantiated from ‘_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, std::allocator<_Tp>) [with _InputIterator = cilk::reducer_opadd<int>*, _ForwardIterator = cilk::reducer_opadd<int>*, _Tp = cilk::reducer_opadd<int>]’ /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/vector.tcc:275: instantiated from ‘void std::vector<_Tp, _Alloc>::_M_insert_aux(__gnu_cxx::__normal_iterator<typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::pointer, std::vector<_Tp, _Alloc> >, const _Tp&) [with _Tp = cilk::reducer_opadd<int>, _Alloc = std::allocator<cilk::reducer_opadd<int> >]’ /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_vector.h:605: instantiated from ‘void std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = cilk::reducer_opadd<int>, _Alloc = std::allocator<cilk::reducer_opadd<int> >]’ geneAttack.cilk:667: instantiated from here /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/cilk++/reducer_opadd.h:229: error: ‘cilk::reducer_opadd<Type>::reducer_opadd(const cilk::reducer_opadd<Type>&) [with Type = int]’ is private /usr/local/cilk/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/stl_construct.h:81: error: within this context make: *** [geneAttack] Error 1 jinchen@galactica:~/workspace/biometrics/genAttack$ make cilk++ geneAttack.cilk -O1 -g -lcilkutil -o geneAttack geneAttack.cilk: In function ‘int cilk cilk_main(int, char**)’: geneAttack.cilk:670: error: expected primary-expression before ‘,’ token geneAttack.cilk:670: error: expected primary-expression before ‘}’ token geneAttack.cilk:674: error: ‘bitmiss_vec’ was not declared in this scope make: *** [geneAttack] Error 1 The Cilk++ manule says it supports array/vector of reducers, although there are performance issues to consider: "If you create a large number of reducers (for example, an array or vector of reducers) you must be aware that there is an overhead at steal and reduce that is proportional to the number of reducers in the program. " Anyone knows what is going on? How should I declare/use vector of reducers? Thank you

    Read the article

  • Interacting with system commands using a web dev language

    - by Jamie
    Hi all, First of all, sorry for the vague title. Let me explain. At work we're currently using SunGrid I've been assigned a project to create a web interface wrapper for interacting with the engine. i.e. displaying users jobs, submitting jobs via a nice GUI etc. (most of the sgrid commands output xml which is nice) My question for you chaps is the following: What web dev language would you use to interact with the system? i.e. use the language to do a system call and evaluate the response. I'm not after an argument on which language is best, I just would like to know which language is specifically good for interacting with the system and is also good for web dev.

    Read the article

  • How to simply this logic/code?

    - by Tattat
    I want to write an apps that accepts user command. The user command is used in this format: command -parameter For example, the app can have "Copy", "Paste", "Delete" command I am thinking the program should work like this : public static void main(String args[]){ if(args[0].equalsIgnoreCase("COPY")){ //handle the copy command } else if(args[0].equalsIgnoreCase("PASTE")){ //handle the copy command }/** code skipped **/ } So, it works, but I think it will become more and more complex when I have more command in my program, also, it is different to read. Any ideas to simply the logic?

    Read the article

  • scripts on Cshell

    - by lego69
    hello, I've got some problem, I have list of data in the file: 053-37878 03828008 Moskovitch James 500 052-34363 01234567 Mendelson Kippi 450 053-32322 03828008 Jameson Shula 350 054-39238 03333333 Merden Moshe 300 is it possible rewrite this list in the same file (without using temporary file) but without last number thanks in advance for any help (I'm talking about C-Shell scripts)

    Read the article

  • How do programmers work together on a project?

    - by Laith J
    Hello, I've always programmed alone, I'm still a student so I never programmed with anyone else, I haven't even used a version control system before. I'm working on a project now that requires knowledge of how programmers work together on a piece of software in a company. How is the software compiled? Is it from the version control system? Is it by individual programmers? Is it periodic? Is it when someone decides to build or something? Are there any tests that are done to make sure it "works"? Anything will do. Thanks.

    Read the article

  • Math/numerical formula every computer programmer should know

    - by aaa
    This is a follow-up question to What should every programmer know and Is mathematics necessary. So the question is, as a computer programmer, what is the most important/useful mathematical or numerical formula that you use? By Formula I mean anything that involves less obvious manipulations, whenever binomial coefficients or bit hacks. I work with multidimensional arrays and various matrix representations. So for me most commonly used formulas are: A(i,j,k,..) = a[i + j*Dim0 + k*Dim0*Dim1 + ... to map indexes to one dimension ( which is basic address calculation which many people do not seem to know). And triangular number T(i) = (i*i + i)/2 which is related to binomial coefficients, used to calculate address in triangular matrixes and many other things. What is your workhorse formula that you think programmer should know?

    Read the article

  • How to determine if an application is using the GPU

    - by Andrew
    I'm looking for a way to determine how to know whether an application is using the GPU with Objective-C. I want to be able to determine if any applications currently running on the system have work going on on the GPU (ie: a reason why the latest MacBook Pros would switch to the discrete graphics over the Intel HD graphics). I've tried getting the information by crossing the list of active windows with the list of windows that have their backing location stored in video memory using Quartz Window Services, but all that does is return the Dock application and I have other applications open that I know are using the GPU (Photoshop CS5, Interface Builder), that and the Dock doesn't require the 330m.

    Read the article

  • How Search Engine Bots Crawl Forums?

    - by Waleed Eissa
    If I have a forums site with a large number of threads, will the search engine bot crawl the whole site every time? Say I have over 1,000,000 threads in my site, will they get crawled every time the bot crawls my site? or how does it work? I want my website to be indexed but I don't want the bot to kill my website! In other words I don't want the bot to keep crawling the old threads again and again every time it crawls my website. Also, what about the pages crawled before? Will the bot request them every time it crawls my website to make sure they are still on the site? I'm asking this because I only link to the latest threads, i.e. there's a page that contains a list of all the latest threads, but I don't link to the older threads, they have to be explicitly requested by URL, e.g. http://www.mysite.com/showthread.aspx?threadid=7 , will this work to stop the bot from bringing my site down and consuming all my bandwidth? P.S. The site is still under development but I want to know in order to design the site so that search engine bots don't bring it down. Thanks

    Read the article

  • Microsoft Solver Foundation constraint

    - by emaster70
    Hello, I'm trying to use Microsoft Solver Foundation 2 to solve a fairly complicated situation, however I'm stuck with an UnsupportedModelException even when I dumb down the model as much as possible. Does anyone have an idea of what I'm doing wrong? Following is the least example required to reproduce the problematic behavior. var ctx = SolverContext.GetContext(); var model = ctx.CreateModel(); var someConstant = 1337.0; var decisionA = new Decision(Domain.Real, "decisionA"); var decisionB = new Decision(Domain.Real, "decisionB"); var decisionC = new Decision(Domain.Real, "decisionC"); model.AddConstraint("ca", decisionA <= someConstant); model.AddConstraint("cb", decisionB <= someConstant); model.AddConstraint("cc", decisionC <= someConstant); model.AddConstraint("mainConstraint", Model.Equal(Model.Sum(decisionA, decisionB, decisionC), someConstant)) model.AddGoal("myComplicatedGoal", GoalKind.Minimize, decisionC); var solution = ctx.Solve(); solution.GetReport().WriteTo(Console.Out); Console.ReadKey(); Please consider that my actual model should include, once complete, a few constraints in the form of a*a+b*a <= someValue, so if what I'm willing to do ultimately isn't supported, please let me know in advance. If that's the case I'd also appreciate a suggestion of some other solver with a .NET friendly interface that I could use (only well-known commercial packages, please). Thanks in advance

    Read the article

  • Make a function which returns the original list except the argument

    - by Alex
    I want make a function which takes a list of string and a string and returns NONE if there is no string in the string list, otherwise it returns SOME of the list of string which is the same as the original list of string except it doesn't contain the initial string (pattern): fun my_function (pattern, source_list) = case source_list of [] => NONE | [x] => if pattern = x then SOME [] else NONE | x::xs => if pattern = x then SOME (xs) else SOME (x) :: my_function (pattern, xs) (* this is wrong, what to do here?*) val a = my_function ("haha", ["12", "aaa", "bbb", "haha", "ccc", "ddd"]) (* should be SOME ["12", "aaa", "bbb", "ccc", "ddd"]*) val a2 = my_function ("haha2", ["123", "aaa", "bbb", "haha", "ccc"]) (*should be NONE*) val a3 = my_function ("haha3", ["haha3"]) (* should be SOME []*) I'm confused by the 3rd case: x::xs => .... What should do there? Note that I'd like not to use any sml library function.

    Read the article

  • How to File Transfer client to Server?

    - by Phsika
    i try to recieve a file from server but give me error on server.Start() ERROR : In a manner not permitted by the access permissions to access a socket was attempted to How can i solve it? private void btn_Recieve_Click(object sender, EventArgs e) { TcpListener server = null; // Set the TcpListener on port 13000. Int32 port = 13000; IPAddress localAddr = IPAddress.Parse("192.168.1.201"); // TcpListener server = new TcpListener(port); server = new TcpListener(localAddr, port); // Start listening for client requests. server.Start(); // Buffer for reading data Byte[] bytes = new Byte[277577]; String data; data = null; // Perform a blocking call to accept requests. // You could also user server.AcceptSocket() here. TcpClient client = server.AcceptTcpClient(); NetworkStream stream = client.GetStream(); int i; i = stream.Read(bytes, 0, 277577); BinaryWriter writer = new BinaryWriter(File.Open("GoodLuckToMe.jpg", FileMode.Create)); writer.Write(bytes); writer.Close(); client.Close(); }

    Read the article

  • Openerp WIth ubuntu 9.04

    - by agbrand
    I had Ubuntu 8.10. I upgrade it to 9.04. I have Openerp5.0 , server/client/web. It worked on 8.10 but not with 9.04. Now when I try to launch my server using: ./openerp-server.py I have this error: ERROR: Import xpath module ERROR: Try to install the old python-xml package It seems that this version of openerp doesn't work with python2.6. Can you help me to redirect openerp to use old version of python please?

    Read the article

  • UI Controls layer on top of operating system.

    - by Mason Blier
    I'm kind of curious about what layer writing a UI platform to the level of Win32 or the X Windowing System would fall in the grand scheme of an operating system. What layers below do they primarily make use of, is it heavily based on direct communication with the graphics card driver (I can't imagine going though a rendering pipeline like OpenGL for this), or is there a graphical platform as part of the operating system which extracts this out a little more. I'm also interested in the creation of shells and the like, and I"m particularly curious as to how people go about creating alternative shells for windows, what do people look for when figuring out what methods to call or what to hook into, etc? I guess I'm fairly lost at these concepts and finding it difficult to find documentation on them. I was initially excited to have taken Operating Systems in college but it was all low level resource management stuff. Thanks all, Mason

    Read the article

  • Why does this Object wonk out & get deleted ?

    - by brainydexter
    Stepping through the debugger, the BBox object is okay at the entry of the function, but as soon as it enters the function, the vfptr object points to 0xccccc. I don't get it. What is causing this ? Why is there a virtual table reference in there when the object is not derived from other class. (Though, it resides in GameObject from which my Player class inherits and I retrieve the BBox from within player. But, why does the BBox have the reference ? Shouldn't it be player who should be maintained in that reference ?) For 1; some code for reference: A. I retrieve the bounding box from player. This returns a bounding box as expected. I then send its address to GetGridCells. const BoundingBox& l_Bbox = l_pPlayer-GetBoundingBox(); boost::unordered_set < Cell*, CellPHash & l_GridCells = GetGridCells ( &l_Bbox ); B. This is where a_pBoundingBox goes crazy and gets that garbage value. boost::unordered_set< Cell*, CellPHash CollisionMgr::GetGridCells(const BoundingBox *a_pBoundingBox) { I think the following code is also pertinent, so I'm sticking this in here anyways: const BoundingBox& Player::GetBoundingBox(void) { return BoundingBox( &GetBoundingSphere() ); } const BoundingSphere& Player::GetBoundingSphere(void) { BoundingSphere& l_BSphere = m_pGeomMesh-m_BoundingSphere; l_BSphere.m_Center = GetPosition(); return l_BSphere; } // BoundingBox Constructor BoundingBox(const BoundingSphere* a_pBoundingSphere); Can anyone please give me some idea as to why this is happening? Also, if you want me to post more code, please do let me know. Thanks!

    Read the article

  • How to find minimum weight with maximum cost in 0-1 Knapsack algorithm?

    - by Nitin9791
    I am trying to solve a spoj problem Party Schedule the problem statement is- You just received another bill which you cannot pay because you lack the money. Unfortunately, this is not the first time to happen, and now you decide to investigate the cause of your constant monetary shortness. The reason is quite obvious: the lion's share of your money routinely disappears at the entrance of party localities. You make up your mind to solve the problem where it arises, namely at the parties themselves. You introduce a limit for your party budget and try to have the most possible fun with regard to this limit. You inquire beforehand about the entrance fee to each party and estimate how much fun you might have there. The list is readily compiled, but how do you actually pick the parties that give you the most fun and do not exceed your budget? Write a program which finds this optimal set of parties that offer the most fun. Keep in mind that your budget need not necessarily be reached exactly. Achieve the highest possible fun level, and do not spend more money than is absolutely necessary. Input The first line of the input specifies your party budget and the number n of parties. The following n lines contain two numbers each. The first number indicates the entrance fee of each party. Parties cost between 5 and 25 francs. The second number indicates the amount of fun of each party, given as an integer number ranging from 0 to 10. The budget will not exceed 500 and there will be at most 100 parties. All numbers are separated by a single space. There are many test cases. Input ends with 0 0. Output For each test case your program must output the sum of the entrance fees and the sum of all fun values of an optimal solution. Both numbers must be separated by a single space. Example Sample input: 50 10 12 3 15 8 16 9 16 6 10 2 21 9 18 4 12 4 17 8 18 9 50 10 13 8 19 10 16 8 12 9 10 2 12 8 13 5 15 5 11 7 16 2 0 0 Sample output: 49 26 48 32 now I know that it is an advance version of 0/1 knapsack problem where along with maximum cost we also have to find minimum weight that is less than a a given weight and have maximum cost. so I have used dp to solve this problem but still get a wrong awnser on submission while it is perfectly fine with given test cases. My code is typedef vector<int> vi; #define pb push_back #define FOR(i,n) for(int i=0;i<n;i++) int main() { //freopen("input.txt","r",stdin); while(1) { int W,n; cin>>W>>n; if(W==0 && n==0) break; int K[n+1][W+1]; vi val,wt; FOR(i,n) { int x,y; cin>>x>>y; wt.pb(x); val.pb(y); } FOR(i,n+1) { FOR(w,W+1) { if(i==0 || w==0) { K[i][w]=0; } else if (wt[i-1] <= w) { if(val[i-1] + K[i-1][w-wt[i-1]]>=K[i-1][w]) { K[i][w]=val[i-1] + K[i-1][w-wt[i-1]]; } else { K[i][w]=K[i-1][w]; } } else { K[i][w] = K[i-1][w]; } } } int a1=K[n][W],a2; for(int j=0;j<W;j++) { if(K[n][j]==a1) { a2=j; break; } } cout<<a2<<" "<<a1<<"\n"; } return 0; } Could anyone suggest what am I missing??

    Read the article

  • How to print "Hello, world!" (in every possible way)

    - by Attila Oláh
    Here's what I', trying to do: 1 language: (Python < 3): print "Hello, world!" 2 languages: (Python < 3 & Windows Shell, aka .bat file): rem=""" echo "Hello, world!" exit """ print "Hello, world!" Next step could be something like bash. Since the above one raises an exception, I tried to make it not raise exceptions, like this: rem=""" echo "Hello, world!" exit """ exit="" exit print "Hello, world!" The only issue is, of course, it won't print the hello world. And I really want it to print that hello world for me. Anyone can help with this? Also, any other language would do it, just don't break the previous ones (i.e. the answer still has to be valid Python code and print out the nice hello world greeting when run with Python.) Any ideas are welcome. I'm making this a community wiki so feel free to add ideas to the list.

    Read the article

  • I don't understand how work call_once

    - by SABROG
    Please help me understand how work call_once Here is thread-safe code. I don't understand why this need Thread Local Storage and global_epoch variables. Variable _fast_pthread_once_per_thread_epoch can be changed to constant/enum like {FAST_PTHREAD_ONCE_INIT, BEING_INITIALIZED, FINISH_INITIALIZED}. Why needed count calls in global_epoch? I think this code can be rewriting with logc: if flag FINISH_INITIALIZED do nothing, else go to block with mutexes and this all. #ifndef FAST_PTHREAD_ONCE_H #define FAST_PTHREAD_ONCE_H #include #include typedef sig_atomic_t fast_pthread_once_t; #define FAST_PTHREAD_ONCE_INIT SIG_ATOMIC_MAX extern __thread fast_pthread_once_t _fast_pthread_once_per_thread_epoch; #ifdef __cplusplus extern "C" { #endif extern void fast_pthread_once( pthread_once_t *once, void (*func)(void) ); inline static void fast_pthread_once_inline( fast_pthread_once_t *once, void (*func)(void) ) { fast_pthread_once_t x = *once; /* unprotected access */ if ( x _fast_pthread_once_per_thread_epoch ) { fast_pthread_once( once, func ); } } #ifdef __cplusplus } #endif #endif FAST_PTHREAD_ONCE_H Source fast_pthread_once.c The source is written in C. The lines of the primary function are numbered for reference in the subsequent correctness argument. #include "fast_pthread_once.h" #include static pthread_mutex_t mu = PTHREAD_MUTEX_INITIALIZER; /* protects global_epoch and all fast_pthread_once_t writes */ static pthread_cond_t cv = PTHREAD_COND_INITIALIZER; /* signalled whenever a fast_pthread_once_t is finalized */ #define BEING_INITIALIZED (FAST_PTHREAD_ONCE_INIT - 1) static fast_pthread_once_t global_epoch = 0; /* under mu */ __thread fast_pthread_once_t _fast_pthread_once_per_thread_epoch; static void check( int x ) { if ( x == 0 ) abort(); } void fast_pthread_once( fast_pthread_once_t *once, void (*func)(void) ) { /*01*/ fast_pthread_once_t x = *once; /* unprotected access */ /*02*/ if ( x _fast_pthread_once_per_thread_epoch ) { /*03*/ check( pthread_mutex_lock(µ) == 0 ); /*04*/ if ( *once == FAST_PTHREAD_ONCE_INIT ) { /*05*/ *once = BEING_INITIALIZED; /*06*/ check( pthread_mutex_unlock(µ) == 0 ); /*07*/ (*func)(); /*08*/ check( pthread_mutex_lock(µ) == 0 ); /*09*/ global_epoch++; /*10*/ *once = global_epoch; /*11*/ check( pthread_cond_broadcast(&cv;) == 0 ); /*12*/ } else { /*13*/ while ( *once == BEING_INITIALIZED ) { /*14*/ check( pthread_cond_wait(&cv;, µ) == 0 ); /*15*/ } /*16*/ } /*17*/ _fast_pthread_once_per_thread_epoch = global_epoch; /*18*/ check (pthread_mutex_unlock(µ) == 0); } } This code from BOOST: #ifndef BOOST_THREAD_PTHREAD_ONCE_HPP #define BOOST_THREAD_PTHREAD_ONCE_HPP // once.hpp // // (C) Copyright 2007-8 Anthony Williams // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #include #include #include #include "pthread_mutex_scoped_lock.hpp" #include #include #include namespace boost { struct once_flag { boost::uintmax_t epoch; }; namespace detail { BOOST_THREAD_DECL boost::uintmax_t& get_once_per_thread_epoch(); BOOST_THREAD_DECL extern boost::uintmax_t once_global_epoch; BOOST_THREAD_DECL extern pthread_mutex_t once_epoch_mutex; BOOST_THREAD_DECL extern pthread_cond_t once_epoch_cv; } #define BOOST_ONCE_INITIAL_FLAG_VALUE 0 #define BOOST_ONCE_INIT {BOOST_ONCE_INITIAL_FLAG_VALUE} // Based on Mike Burrows fast_pthread_once algorithm as described in // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2444.html template void call_once(once_flag& flag,Function f) { static boost::uintmax_t const uninitialized_flag=BOOST_ONCE_INITIAL_FLAG_VALUE; static boost::uintmax_t const being_initialized=uninitialized_flag+1; boost::uintmax_t const epoch=flag.epoch; boost::uintmax_t& this_thread_epoch=detail::get_once_per_thread_epoch(); if(epoch #endif I right understand, boost don't use atomic operation, so code from boost not thread-safe?

    Read the article

  • [Perl] Testing for EAGAIN / EWOULDBLOCK on a recv

    - by Robert S. Barnes
    I'm testing a socket to see if it's still open: my $dummy = ''; my $ret = recv($sock, $dummy, 1, MSG_DONTWAIT | MSG_PEEK); if (!defined $ret || (length($dummy) == 0 && $! != EAGAIN && $! != EWOULDBLOCK )) { logerr("Broken pipe? ".__LINE__." $!"); } else { # socket still connected, reuse logerr(__LINE__.": $!"); return $sock; } I'm passing this code a socket I know for certain is open and it's always going through the first branch and logging "Broken pipe? 149 Resource temporarily unavailable". I don't understand how this is happening since "Resource temporarily unavailable" is supposed to correspond to EAGAIN as far as I know. I'm sure there must be something simple I'm missing. And yes, I know this is not a full proof way to test and I account for that.

    Read the article

  • Is Haskell "mainstream", or is it mainly used by hobbyists and academics?

    - by Asher
    I came across a post where someone wrote something inaccurate about Haskell (won't go into it) and he got flammed for it. Which (pleasantly) surprised me. About 3 years ago I read this joke about Haskell: All the haskell programmers in the world can fit into a 747 and if that plane were to crash no one would care... or something along those lines. Which brings me to my question: how healthy is the Haskell community, anyway? Is Haskell "mainstream"? Is it mainly used by hobbiest and academics or someone making some serious money from it (which is the true yardstick of how good a language is - just kidding, geez!)?

    Read the article

< Previous Page | 262 263 264 265 266 267 268 269 270 271 272 273  | Next Page >