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How to create custom config section in

You can extend ASP.NET configuration settings with XML configuration elements of
your own. To do this, you create a custom configuration section handler.
The handler must be a .NET Framework class that inherits from 
the System.Configuration.ConfigurationSection class. The section handler 
interprets and processes the settings that are defined in XML configuration 
elements in a specific section of a Web.config file. You can read and write 
these settings through the handler's properties.
using System; using System.Collections.Generic; using System.Configuration; using System.Linq; using System.Web; namespace CustomConfigSection { publicclass LoginRedirectByRoleSection : ConfigurationSection { [ConfigurationProperty("roleRedirects")] public RoleRedirectCollection RoleRedirects { get { return (RoleRedirectCollection)this["roleRedirects"]; } set { this["roleRedirects"] = valu…

How to read webpage asynchronously in c#

most programming languages a called method is executed synchronously, i.e. in the thread of execution from which it is invoked. If the method needs a long time to completion, e.g. because it is loading data over the internet, the calling thread is blocked until the method has finished. When this is not desired, it is possible to start a "worker thread" and invoke the method from there. In most programming environments this requires many lines of code, especially if care is taken to avoid the overhead that may be caused by creating many threads. AMI solves this problem in that it augments a potentially long-running ("synchronous") object method with an "asynchronous" variant that returns immediately, along with additional methods that make it easy to receive notification of completion, or to wait for completion at a later time.

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Net; using System.Threading; na…

Silverlight MVVM

What is MVVM pattern as per wikipedia "The Model View ViewModel (MVVM) is an architectural pattern used in software engineering that originated from Microsoft as a specialization of the Presentation Model design pattern introduced by Martin Fowler.[1] Largely based on the model–view–controller pattern (MVC), MVVM is a specific implementation targeted at UI development platforms which support the event-driven programming in Windows Presentation Foundation (WPF) and Silverlight on the .NET platforms using XAML and .NET languages. Technically different, but similar, Presentation Model design patterns are available in HTML5[2][3] through KnockoutJS, and for Java the ZK framework (Model-View-Binder)." ViewModelBase.csusing System; using System.ComponentModel; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Ink; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; u…

Kth Largest Element in Array

publicclass KthElement { publicstaticint kthElement(int[] arr, int k) { int n = arr.Length; int lo = 0; int hi = n - 1; if (lo == hi) return arr[lo]; while (true) { int pivotIndex = Partition(arr, lo, hi); int rank = pivotIndex - lo + 1; if (rank == k) return arr[pivotIndex]; elseif (k < rank) return kthElement(arr, k); elsereturn kthElement(arr, k - rank); } } privatestaticint Partition(int[] arr, int left, int right) { int pivot = arr[left]; int i = left + 1; int j = right; while (i < j) { while (arr[i] <pivot) i++; while (arr[j] >= pivot) j--; if (i < j) Swap(arr, i, j); } Swap(arr, left, j); return j; } privatestaticvoid Swap(int[] arr, int i, int j) { int temp = arr[i]; arr[i] = arr[j]; …

Levenshtein distance (Edit distance)

The edit distance of two strings, s1 and s2, is defined as the minimum number of point mutations required to change s1 into s2, where a point mutation is one of:

change a letter,insert a letter, ordelete a letter

class EditDistanceAlgo { staticint[,] m; publicstaticchar diagCh; publicstaticint LevenshteinDistance(string s, string t) { int[,] d = newint[s.Length + 1, t.Length + 1]; for (int i = 0; i <= s.Length; i++) d[i, 0] = i; for (int j = 0; j <= t.Length; j++) d[0, j] = j; for (int j = 1; j <= t.Length; j++) for (int i = 1; i <= s.Length; i++) if (s[i - 1] == t[j - 1]) d[i, j] = d[i - 1, j - 1]; //no operationelse d[i, j] = Math.Min(Math.Min( d[i - 1, j] + 1, //a deletion d[i, j - 1] + 1), //an insertion d[i - 1, j - 1] +…

Longest increasing subsequence problem (Dynamic Programming)

The input consists of two sequences ~x = x1, . . . , xn and ~y = y1, . . . , ym. The goal is to find a longest common subsequence of ~x and ~y, that is a sequence z1, . . . , zk that is a subsequence both of ~x and of ~y. Note that a subsequence is not always substring: if ~z is a subsequence of ~x, and zi = xj and zi+1 = xj 0, then the only requirement is that j 0 > j, whereas for a substring it would have to be j 0 = j + 1.For example, let ~x and ~y be two DNA strings ~x = T GACT A and ~y = GT GCAT G; n = 6 and m = 7. Then one common subsequence would be GT A. However, it is not the longest possible common subsequence: there are common subsequences T GCA, T GAT and T GCT of length 4

0/1 Knapsack problem


using System; publicclass Knapsack { staticint nbObjects = 8; staticint[] weight = { 2, 3, 5, 2, 4, 6, 3, 1 }; staticint[] utility = { 5, 8, 14, 6, 13, 17, 10, 4 }; staticint weightmax = 12; staticint[,] array; staticvoid Display() { int i, u, w; u = 0; w = weightmax; for (i = nbObjects - 1; i >= 1; i--) { if (array[i, w] != array[i - 1, w]) { Console.Write((i + 1) + " "); w = w - weight[i]; u = u + utility[i]; } } if (array[0, w] != 0) { Console.WriteLine("1"); w = w - weight[0]; u = u + utility[0]; } } publicstaticvoid SolveDP() { array = newint[nbObjects, weightmax + 1]; // initialize the first rowfor (int j = 0; j <= weightmax; j++) if (j < weight[0]) { arr…