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    copied!<p>Interesting answers. Thank you for the pointers to wikipedia - whilst interesting - they don't actually solve the problem as stated as I was looking for exact matches - more of an accounting / book blancing problem than a traditional bin-packing / knapsack problem.</p> <p>I have been following the development of stack overflow with interest and wondered how useful it would be. This problem came up at work and I wondered whether stack overflow could provide a ready made answer (or a better answer) quicker than I could write it myself. Thanks also for the comments suggesting this be tagged homework - I guess that is reasonably accurate in light of the above.</p> <p>For those who are interested, here is my solution which uses recursion (naturally) I also changed my mind about the method signature and went for List> rather than decimal[][] as the return type:</p> <pre><code>public class Solver { private List&lt;List&lt;decimal&gt;&gt; mResults; public List&lt;List&lt;decimal&gt;&gt; Solve(decimal goal, decimal[] elements) { mResults = new List&lt;List&lt;decimal&gt;&gt;(); RecursiveSolve(goal, 0.0m, new List&lt;decimal&gt;(), new List&lt;decimal&gt;(elements), 0); return mResults; } private void RecursiveSolve(decimal goal, decimal currentSum, List&lt;decimal&gt; included, List&lt;decimal&gt; notIncluded, int startIndex) { for (int index = startIndex; index &lt; notIncluded.Count; index++) { decimal nextValue = notIncluded[index]; if (currentSum + nextValue == goal) { List&lt;decimal&gt; newResult = new List&lt;decimal&gt;(included); newResult.Add(nextValue); mResults.Add(newResult); } else if (currentSum + nextValue &lt; goal) { List&lt;decimal&gt; nextIncluded = new List&lt;decimal&gt;(included); nextIncluded.Add(nextValue); List&lt;decimal&gt; nextNotIncluded = new List&lt;decimal&gt;(notIncluded); nextNotIncluded.Remove(nextValue); RecursiveSolve(goal, currentSum + nextValue, nextIncluded, nextNotIncluded, startIndex++); } } } } </code></pre> <p>If you want an app to test this works, try this console app code:</p> <pre><code>class Program { static void Main(string[] args) { string input; decimal goal; decimal element; do { Console.WriteLine("Please enter the goal:"); input = Console.ReadLine(); } while (!decimal.TryParse(input, out goal)); Console.WriteLine("Please enter the elements (separated by spaces)"); input = Console.ReadLine(); string[] elementsText = input.Split(' '); List&lt;decimal&gt; elementsList = new List&lt;decimal&gt;(); foreach (string elementText in elementsText) { if (decimal.TryParse(elementText, out element)) { elementsList.Add(element); } } Solver solver = new Solver(); List&lt;List&lt;decimal&gt;&gt; results = solver.Solve(goal, elementsList.ToArray()); foreach(List&lt;decimal&gt; result in results) { foreach (decimal value in result) { Console.Write("{0}\t", value); } Console.WriteLine(); } Console.ReadLine(); } } </code></pre> <p>I hope this helps someone else get their answer more quickly (whether for homework or otherwise).</p> <p>Cheers...</p>
 

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