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POHow to set values in a multidimensional array using a linear index
 

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    <p>What is the most efficient way of setting values in C# multi-dimensional arrays using a linear index? For example given an array...</p> <pre><code>int[,,] arr2 = { {{0,1,2}, {3,4,5}, {6,7,8}} , {{9,10,11}, {12,13,14}, {15,16,17}} , {{18,19,20}, {21,22,23}, {24,25,26}} }; </code></pre> <p>How do I set all the elements to 30 using a linear index ...</p> <pre><code>//This code does not work for (int i = 0; i &lt; arr.Length; i++) { arr.SetValue(30, i); } </code></pre> <p>Apparently the SetValue() above does not work with multidimensional arrays.</p> <p>Here is the best solution that I could come up with...</p> <p>EDIT: Added some clarifications to the code...</p> <pre><code>static class Program { static void Main(string[] args) { //Sample input. int[,,] arr2 = { {{0,1,2}, {3,4,5}, {6,7,8}} , {{9,10,11}, {12,13,14}, {15,16,17}} , {{18,19,20}, {21,22,23}, {24,25,26}} }; int[] arr1 = { 1, 2, 3, 4 }; setElementsTo30(arr2); setElementsTo30(arr1); } //Must be able to process int arrays of arbitrary dimensions and content private static void setElementsTo30(Array arr) { IList&lt;int&gt; cumulativeLength = getCumulativeLengths(arr); for (int i = 0; i &lt; arr.Length; i++) { SetValue(arr, i, 30, cumulativeLength); } } public static void SetValue(this Array arr, int index, object value, IList&lt;int&gt; cumulativeLength) { int[] arrayIndex = new int[arr.Rank]; for (int dim = arr.Rank-1; dim &gt;= 0; dim--) { arrayIndex[dim] = index / cumulativeLength[dim] % arr.GetLength(dim); } arr.SetValue(value, arrayIndex); } private static IList&lt;int&gt; getCumulativeLengths(Array arr) { List&lt;int&gt; lengths = new List&lt;int&gt;(arr.Rank); for (int dim = 0; dim &lt; arr.Rank; dim++) { int prod = 1; for (int i = dim + 1; i &lt; arr.Rank; i++) { prod *= arr.GetLength(i); } lengths.Add(prod); } return (IList&lt;int&gt;)lengths; } } </code></pre> <p>Is there a way to do the same more efficiently and possibly using something provided by the framework itself (i.e. something which can be used without much hassle.)</p> <p>Thanks,<br> SDX2000.</p>
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