Search Results

Search found 7220 results on 289 pages for 'graph algorithm'.

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 16/289 | < Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >

  • Classical Round Table algorithm?

    - by user1795954
    Coins with different value are spread in circle around a round table . We can choose any coin such that for any two adjacent pair of coins , atleast one must be selected (both maybe selected too) . In such condition we have to find minimum possible value of coins selected . I have to respect time complexity so instead of using naive recursive bruteforce , i tried doing it using dynamic programming . But i get Wrong Answer - my algorithm is incorrect . If someone could suggest an algorithm to do it dynamically , i could code myself in c++ . Also maximum number of coins is 10^6 , so i think O(n) solution exists .

    Read the article

  • [NEWVERSION]algorithm || method to write prog[UNSOLVED] [closed]

    - by fatai
    I am one of the computer science student. Everyone solve problem with a different or same method, ( but actually I dont know whether they use method or I dont know whether there are such common method to approach problem.) if there are common method, What is it ? If there are different method, which method are you using ? All teacher give us problem which in simple form sometimes, but they donot introduce any approach or method(s) so that we cannot make a decision to choose the method then apply that one to problem , afterward find solution then write code.No help from teacher , push us to find method to solve homework. Ex: my friend is using no method , he says "I start to construct algorithm while I try to write prog." I have found one method when I failed the course, More accurately, my method: When I counter problem in language , I will get more paper and then ; first, input/ output step ; my prog will take this / these there argument(s) and return namely X , ex : in c, input length is not known and at same type , so I must use pointer desired output is in form of package , so use structure second, execution part ; in that step , I am writing all step which are goes to final output ex : in python ; 1.) [ + , [- , 4 , [ * , 1 , 2 ]], 5] 2.) [ + , [- , 4 , 2 ],5 ] 3.) [ + , 2 , 5] 4.) 7 ==> return 7 third, I will write test code ex : in c++ input : append 3 4 5 6 vector_x remove 0 1 desired output vector_x holds : 5 6 now, my other question is ; What is/are other method(s) which have/has been; used to construct class :::: for c++ , python, java used to communicate classes / computers used for solving embedded system problem ::::: for c by other user? Some programmer uses generalized method without considering prog-language(java , perl .. ), what is this method ? Why I wonder , because I learn if you dont costruct algorithm on paper, you may achieve your goal. Like no money no lunch , I can say no algorithm no prog therefore , feel free when you write your own method , a way which is introduced by someone else but you are using and you find it is so efficient

    Read the article

  • Algorithm for evaluating nested logical expression

    - by TravelingSalesman
    I have a logical expression that I would like to evaluate. The expression can be nested and consists of T (True) or F (False) and parenthesis. The parenthesis "(" means "logical OR". Two terms TF beside each others (or any other two combinations beside each others), should be ANDED (Logical AND). For example, the expression: ((TFT)T) = true I need an algorithm for solving this problem. I thought of converting the expression first to disjunctive or conjunctive normal form and then I can easily evaluate the expression. However, I couldn't find an algorithm that normalizes the expression. Any suggestions? Thank you. The problem statement can be found here: https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=2&category=378&page=show_problem&problem=2967

    Read the article

  • Fast partial sorting algorithm

    - by trican
    I'm looking for a fast way to do a partial sort of 81 numbers - Ideally I'm looking to extract the lowest 16 values (its not necessary for the 16 to be in the absolutely correct order). The target for this is dedicated hardware in an FPGA - so this slightly complicated matters as I want the area of the resultant implementation as small as possible. I looked at and implemented the odd-even merge sort algorithm, but I'm ideally looking for anything that might be more efficient for my needs (trade algorithm implementation size for a partial sort giving lowest 16, not necessarily in order as opposed to a full sort) Any suggestions would be very welcome Many thanks

    Read the article

  • Coming Up with a Good Algorithm for a Simple Idea

    - by mkoryak
    I need to come up with an algorithm that does the following: Lets say you have an array of positive numbers (e.g. [1,3,7,0,0,9]) and you know beforehand their sum is 20. You want to abstract some average amount from each number such that the new sum would be less by 7. To do so, you must follow these rules: you can only subtract integers the resulting array must not have any negative values you can not make any changes to the indices of the buckets. The more uniformly the subtraction is distributed over the array the better. Here is my attempt at an algorithm in JavaScript + underscore (which will probably make it n^2): function distributeSubtraction(array, goal){ var sum = _.reduce(arr, function(x, y) { return x + y; }, 0); if(goal < sum){ while(goal < sum && goal > 0){ var less = ~~(goal / _.filter(arr, _.identity).length); //length of array without 0s arr = _.map(arr, function(val){ if(less > 0){ return (less < val) ? val - less : val; //not ideal, im skipping some! } else { if(goal > 0){ //again not ideal. giving preference to start of array if(val > 0) { goal--; return val - 1; } } else { return val; } } }); if(goal > 0){ var newSum = _.reduce(arr, function(x, y) { return x + y; }, 0); goal -= sum - newSum; sum = newSum; } else { return arr; } } } else if(goal == sum) { return _.map(arr, function(){ return 0; }); } else { return arr; } } var goal = 7; var arr = [1,3,7,0,0,9]; var newArray = distributeSubtraction(arr, goal); //returned: [0, 1, 5, 0, 0, 7]; Well, that works but there must be a better way! I imagine the run time of this thing will be terrible with bigger arrays and bigger numbers. edit: I want to clarify that this question is purely academic. Think of it like an interview question where you whiteboard something and the interviewer asks you how your algorithm would behave on a different type of a dataset.

    Read the article

  • Algorithm to determine coin combinations

    - by A.J.
    I was recently faced with a prompt for a programming algorithm that I had no idea what to do for. I've never really written an algorithm before, so I'm kind of a newb at this. The problem said to write a program to determine all of the possible coin combinations for a cashier to give back as change based on coin values and number of coins. For example, there could be a currency with 4 coins: a 2 cent, 6 cent, 10 cent and 15 cent coins. How many combinations of this that equal 50 cents are there? The language I'm using is C++, although that doesn't really matter too much. edit: This is a more specific programming question, but how would I analyze a string in C++ to get the coin values? They were given in a text document like 4 2 6 10 15 50 (where the numbers in this case correspond to the example I gave)

    Read the article

  • I need an algorithm to find the best path

    - by user242635
    I need an algorithm to find the best solution of a path finding problem. The problem can be stated as: At the starting point I can proceed along multiple different paths. At each step there are another multiple possible choices where to proceed. There are two operations possible at each step: A boundary condition that determine if a path is acceptable or not. A condition that determine if the path has reached the final destination and can be selected as the best one. At each step a number of paths can be eliminated, letting only the "good" paths to grow. I hope this sufficiently describes my problem, and also a possible brute force solution. My question is: is the brute force is the best/only solution to the problem, and I need some hint also about the best coding structure of the algorithm.

    Read the article

  • How should I change my Graph structure (very slow insertion)?

    - by Nazgulled
    Hi, This program I'm doing is about a social network, which means there are users and their profiles. The profiles structure is UserProfile. Now, there are various possible Graph implementations and I don't think I'm using the best one. I have a Graph structure and inside, there's a pointer to a linked list of type Vertex. Each Vertex element has a value, a pointer to the next Vertex and a pointer to a linked list of type Edge. Each Edge element has a value (so I can define weights and whatever it's needed), a pointer to the next Edge and a pointer to the Vertex owner. I have a 2 sample files with data to process (in CSV style) and insert into the Graph. The first one is the user data (one user per line); the second one is the user relations (for the graph). The first file is quickly inserted into the graph cause I always insert at the head and there's like ~18000 users. The second file takes ages but I still insert the edges at the head. The file has about ~520000 lines of user relations and takes between 13-15mins to insert into the Graph. I made a quick test and reading the data is pretty quickly, instantaneously really. The problem is in the insertion. This problem exists because I have a Graph implemented with linked lists for the vertices. Every time I need to insert a relation, I need to lookup for 2 vertices, so I can link them together. This is the problem... Doing this for ~520000 relations, takes a while. How should I solve this? Solution 1) Some people recommended me to implement the Graph (the vertices part) as an array instead of a linked list. This way I have direct access to every vertex and the insertion is probably going to drop considerably. But, I don't like the idea of allocating an array with [18000] elements. How practically is this? My sample data has ~18000, but what if I need much less or much more? The linked list approach has that flexibility, I can have whatever size I want as long as there's memory for it. But the array doesn't, how am I going to handle such situation? What are your suggestions? Using linked lists is good for space complexity but bad for time complexity. And using an array is good for time complexity but bad for space complexity. Any thoughts about this solution? Solution 2) This project also demands that I have some sort of data structures that allows quick lookup based on a name index and an ID index. For this I decided to use Hash Tables. My tables are implemented with separate chaining as collision resolution and when a load factor of 0.70 is reach, I normally recreate the table. I base the next table size on this http://planetmath.org/encyclopedia/GoodHashTablePrimes.html. Currently, both Hash Tables hold a pointer to the UserProfile instead of duplication the user profile itself. That would be stupid, changing data would require 3 changes and it's really dumb to do it that way. So I just save the pointer to the UserProfile. The same user profile pointer is also saved as value in each Graph Vertex. So, I have 3 data structures, one Graph and two Hash Tables and every single one of them point to the same exact UserProfile. The Graph structure will serve the purpose of finding the shortest path and stuff like that while the Hash Tables serve as quick index by name and ID. What I'm thinking to solve my Graph problem is to, instead of having the Hash Tables value point to the UserProfile, I point it to the corresponding Vertex. It's still a pointer, no more and no less space is used, I just change what I point to. Like this, I can easily and quickly lookup for each Vertex I need and link them together. This will insert the ~520000 relations pretty quickly. I thought of this solution because I already have the Hash Tables and I need to have them, then, why not take advantage of them for indexing the Graph vertices instead of the user profile? It's basically the same thing, I can still access the UserProfile pretty quickly, just go to the Vertex and then to the UserProfile. But, do you see any cons on this second solution against the first one? Or only pros that overpower the pros and cons on the first solution? Other Solution) If you have any other solution, I'm all ears. But please explain the pros and cons of that solution over the previous 2. I really don't have much time to be wasting with this right now, I need to move on with this project, so, if I'm doing to do such a change, I need to understand exactly what to change and if that's really the way to go. Hopefully no one fell asleep reading this and closed the browser, sorry for the big testament. But I really need to decide what to do about this and I really need to make a change. P.S: When answering my proposed solutions, please enumerate them as I did so I know exactly what are you talking about and don't confuse my self more than I already am.

    Read the article

  • Is there any algorithm for finding LINES by PIXEL COLORS on picture?

    - by Ole Jak
    So I have Image like this I want to get something like this (I hevent drawn all lines I want but I hope you can get my idea) I need algorithm for finding all straight lines on it by just reading colors of pixels. No hard math, no Haar, no Hough. Some algorithm which would be based on points colors. I want to give to algorithm parameters like min line length and max line distortion. I want to get relative to picture pixel coords start and end points of lines. So I need algorithm for finding straight lines of different colors on picture. Algorithm which would be based on idea of image of different colors and Lines of static colors. Yes - such algorithm will not work for images with lots of shadows and lights. But It willl probably be fast (I hope so). Is there any such algorithm?

    Read the article

  • How do I find all paths through a set of given nodes in a DAG?

    - by Hanno Fietz
    I have a list of items (blue nodes below) which are categorized by the users of my application. The categories themselves can be grouped and categorized themselves. The resulting structure can be represented as a Directed Acyclic Graph (DAG) where the items are sinks at the bottom of the graph's topology and the top categories are sources. Note that while some of the categories might be well defined, a lot is going to be user defined and might be very messy. Example: On that structure, I want to perform the following operations: find all items (sinks) below a particular node (all items in Europe) find all paths (if any) that pass through all of a set of n nodes (all items sent via SMTP from example.com) find all nodes that lie below all of a set of nodes (intersection: goyish brown foods) The first seems quite straightforward: start at the node, follow all possible paths to the bottom and collect the items there. However, is there a faster approach? Remembering the nodes I already passed through probably helps avoiding unnecessary repetition, but are there more optimizations? How do I go about the second one? It seems that the first step would be to determine the height of each node in the set, as to determine at which one(s) to start and then find all paths below that which include the rest of the set. But is this the best (or even a good) approach? The graph traversal algorithms listed at Wikipedia all seem to be concerned with either finding a particular node or the shortest or otherwise most effective route between two nodes. I think both is not what I want, or did I just fail to see how this applies to my problem? Where else should I read?

    Read the article

  • Algorithm for finding the best routes for food distribution in game

    - by Tautrimas
    Hello, I'm designing a city building game and got into a problem. Imagine Sierra's Caesar III game mechanics: you have many city districts with one market each. There are several granaries over the distance connected with a directed weighted graph. The difference: people (here cars) are units that form traffic jams (here goes the graph weights). Note: in Ceasar game series, people harvested food and stockpiled it in several big granaries, whereas many markets (small shops) took food from the granaries and delivered it to the citizens. The task: tell each district where they should be getting their food from while taking least time and minimizing congestions on the city's roads. Map example Sample diagram Suppose that yellow districts need 7, 7 and 4 apples accordingly. Bluish granaries have 7 and 11 apples accordingly. Suppose edges weights to be proportional to their length. Then, the solution should be something like the gray numbers indicated on the edges. Eg, first district gets 4 apples from the 1st and 3 apples from the 2nd granary, while the last district gets 4 apples from only the 2nd granary. Here, vertical roads are first occupied to the max, and then the remaining workers are sent to the diagonal paths. Question What practical and very fast algorithm should I use? I was looking at some papers (Congestion Games: Optimization in Competition etc.) describing congestion games, but could not get the big picture. Any help is very appreciated! P. S. I can post very little links and no images because of new user restriction.

    Read the article

  • Oauth Logout using facebook graph api

    - by Sam
    Hi, I just made a website where i'm authorizing the users using the oauth2.0 and graph api. I also want to user logout from my website and facebook site,when they click on the logout button. I'm unable to find a solution for this last 24 hours.My code is in asp.net. Thanks in Advacnce

    Read the article

  • Facebook Friends.getAppUsers using Graph API

    - by Richard
    I have an application that uses the old REST API call Friends.getAppUsers to get the list of friends for the current user that have authorized my application. I have read the docs, but I can't figure out how to do this with the Graph API. Can someone give me an example?

    Read the article

  • How to use Koala Facebook Graph API?

    - by reko
    I am a Rails newbie. I want to use Koala's Graph API. In my controller @graph = Koala::Facebook::API.new('myFacebookAccessToken') @hello = @graph.get_object("my.Name") When I do this, I get something like this { "id"=>"123456", "name"=>"First Middle Last", "first_name"=>"First", "middle_name"=>"Middle", "last_name"=>"Last", "link"=>"http://www.facebook.com/MyName", "username"=>"my.name", "birthday"=>"12/12/1212", "hometown"=>{"id"=>"115200305133358163", "name"=>"City, State"}, "location"=>{"id"=>"1054648928202133335", "name"=>"City, State"}, "bio"=>"This is my awesome Bio.", "quotes"=>"I am the master of my fate; I am the captain of my soul. - William Ernest Henley\r\n\r\n"Don't go around saying the world owes you a living. The world owes you nothing. It was here first.\" - Mark Twain", "work"=>[{"employer"=>{"id"=>"100751133333", "name"=>"Company1"}, "position"=>{"id"=>"105763693332790962", "name"=>"Position1"}, "start_date"=>"2010-08", "end_date"=>"2011-07"}], "sports"=>[{"id"=>"104019549633137", "name"=>"Sport1"}, {"id"=>"103992339636529", "name"=>"Sport2"}], "favorite_teams"=>[{"id"=>"105467226133353743", "name"=>"Fav1"}, {"id"=>"19031343444432369133", "name"=>"Fav2"}, {"id"=>"98027790139333", "name"=>"Fav3"}, {"id"=>"104055132963393331", "name"=>"Fav4"}, {"id"=>"191744431437533310", "name"=>"Fav5"}], "favorite_athletes"=>[{"id"=>"10836600585799922", "name"=>"Fava1"}, {"id"=>"18995689436787722", "name"=>"Fava2"}, {"id"=>"11156342219404022", "name"=>"Fava4"}, {"id"=>"11169998212279347", "name"=>"Fava5"}, {"id"=>"122326564475039", "name"=>"Fava6"}], "inspirational_people"=>[{"id"=>"16383141733798", "name"=>"Fava7"}, {"id"=>"113529011990793335", "name"=>"fava8"}, {"id"=>"112032333138809855566", "name"=>"Fava9"}, {"id"=>"10810367588423324", "name"=>"Fava10"}], "education"=>[{"school"=>{"id"=>"13478880321332322233663", "name"=>"School1"}, "type"=>"High School", "with"=>[{"id"=>"1401052755", "name"=>"Friend1"}]}, {"school"=>{"id"=>"11482777188037224", "name"=>"School2"}, "year"=>{"id"=>"138383069535219", "name"=>"2005"}, "type"=>"High School"}, {"school"=>{"id"=>"10604484633093514", "name"=>"School3"}, "year"=>{"id"=>"142963519060927", "name"=>"2010"}, "concentration"=>[{"id"=>"10407695629335773", "name"=>"c1"}], "type"=>"College"}, {"school"=>{"id"=>"22030497466330708", "name"=>"School4"}, "degree"=>{"id"=>"19233130157477979", "name"=>"c3"}, "year"=>{"id"=>"201638419856163", "name"=>"2011"}, "type"=>"Graduate School"}], "gender"=>"male", "interested_in"=>["female"], "relationship_status"=>"Single", "religion"=>"Religion1", "political"=>"Political1", "email"=>"[email protected]", "timezone"=>-8, "locale"=>"en_US", "languages"=>[{"id"=>"10605952233759137", "name"=>"English"}, {"id"=>"10337617475934611", "name"=>"L2"}, {"id"=>"11296944428713061", "name"=>"L3"}], "verified"=>true, "updated_time"=>"2012-02-24T04:18:05+0000" } How do I show this entire hash in the view in a good format? This is what I did from what ever I learnt.. In my view <% @hello.each do |key, value| %> <li><%=h "#{key.to_s} : #{value.to_s}" %></li> <% end %> This will get the entire thing converted to a list... It works awesome if its just one key.. but how to work with multiple keys and show only the information... something like when it outputs hometown : City, State rather than something like hometown : {"id"=>"115200305133358163", "name"=>"City, State"} Also for education if I just say education[school][name] to display list of schools attended? The error i get is can't convert String into Integer I also tried to do this in my controller, but I get the same error.. @fav_teams = @hello["favorite_teams"]["name"] Also, how can I save all these to the database.. something like just the list of all schools.. not their id no's? Update: The way I plan to save to my database is.. lets say for a user model, i want to save to database as :facebook_id, :facebook_name, :facebook_firstname, ...., :facebook_hometown .. here I only want to save name... when it comes to education.. I want to save.. school, concentration and type.. I have no idea on how to achieve this.. Looking forward for help! thanks!

    Read the article

  • Google visualization API Junk characters in the generated graph

    - by vimson
    I am using google visulization API for one of my project in Arabic. My problem is in the generated graph Arabic characters seems to be Junk characters. data.addColumn('number', '?????'); data.addColumn('number', '?????'); I am using Visualization API for generating Line and Bar charts. Can anyone please suggest a solution for this?

    Read the article

  • Set different line format for a graph with more than one serie with pChart

    - by woodgate
    I am actually using the pChart PHP library for generate graphs. I wanna know if it's possible to give a different line format for a graph with multiple series. I need a line with for example 3px of width but other line with 1px of width. Is that possible? In the official documentation only appears a function that give format to the lines of all series: http://pchart.sourceforge.net/documentation.php?topic=pChart#setLineStyle Thanks a lot.

    Read the article

  • Finding minimum cut-sets between bounded subgraphs

    - by Tore
    If a game map is partitioned into subgraphs, how to minimize edges between subgraphs? I have a problem, Im trying to make A* searches through a grid based game like pacman or sokoban, but i need to find "enclosures". What do i mean by enclosures? subgraphs with as few cut edges as possible given a maximum size and minimum size for number of vertices for each subgraph that act as a soft constraints. Alternatively you could say i am looking to find bridges between subgraphs, but its generally the same problem. Given a game that looks like this, what i want to do is find enclosures so that i can properly find entrances to them and thus get a good heuristic for reaching vertices inside these enclosures. So what i want is to find these colored regions on any given map. My Motivation The reason for me bothering to do this and not just staying content with the performance of a simple manhattan distance heuristic is that an enclosure heuristic can give more optimal results and i would not have to actually do the A* to get some proper distance calculations and also for later adding competitive blocking of opponents within these enclosures when playing sokoban type games. Also the enclosure heuristic can be used for a minimax approach to finding goal vertices more properly. A possible solution to the problem is the Kernighan-Lin algorithm: function Kernighan-Lin(G(V,E)): determine a balanced initial partition of the nodes into sets A and B do A1 := A; B1 := B compute D values for all a in A1 and b in B1 for (i := 1 to |V|/2) find a[i] from A1 and b[i] from B1, such that g[i] = D[a[i]] + D[b[i]] - 2*c[a][b] is maximal move a[i] to B1 and b[i] to A1 remove a[i] and b[i] from further consideration in this pass update D values for the elements of A1 = A1 / a[i] and B1 = B1 / b[i] end for find k which maximizes g_max, the sum of g[1],...,g[k] if (g_max > 0) then Exchange a[1],a[2],...,a[k] with b[1],b[2],...,b[k] until (g_max <= 0) return G(V,E) My problem with this algorithm is its runtime at O(n^2 * lg(n)), i am thinking of limiting the nodes in A1 and B1 to the border of each subgraph to reduce the amount of work done. I also dont understand the c[a][b] cost in the algorithm, if a and b do not have an edge between them is the cost assumed to be 0 or infinity, or should i create an edge based on some heuristic. Do you know what c[a][b] is supposed to be when there is no edge between a and b? Do you think my problem is suitable to use a multi level problem? Why or why not? Do you have a good idea for how to reduce the work done with the kernighan-lin algorithm for my problem?

    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 | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >