C#

Skippums wrote:

1. I cannot figure out how to modify the contents of an IEnumerable object.

for (int i = 0; i < list.Count; i++)
{
  list[i] = tempArray[indexes[j++]];
}

Pete O'Hanlon wrote:

Note that this isn't possible for something like a LinkedList.

BobJanova wrote:

You can't modify a Queue or a Stack via array indexing

public static class Permutation {

    // Random number generator
    private static Random rand = new Random();

    // Permute a collection of objects, returning an array
    public static T[] Permute<T>(IEnumerable<T> list) {
        // Create a copy of the input array
        T[] permArray = list.ToArray();
        long arraySize = permArray.LongLength;
 
        // Create a permutation of indexes
        long[] perm = Permutation.Random(arraySize);

        // Assign the new values to the existing ordered collection
        long i = 0;
        foreach (T item in list) {
            permArray[perm[i++]] = item;
        }

        // Return the permuted array
        return permArray;
    }

    // Generates a random permutation of the integers in the range [0, size)
    public static long[] Random(long size) {
        long[] perm = new long[size];
        lock(rand) {
            for (long i = size - 2; i >= 0; --i) {
                // I implemented the extension method Random.NextInt64
                perm[i] = rand.NextInt64(size - i);
                for (long j = i + 1; j < size; ++j) {
                    if (perm[i] <= perm[j])
                        ++perm[j];
                }
            }
        }
        return perm;
    }
}

Skippums wrote:

make the method that returns the array public

PIEBALDconsult wrote:

something like a RandomSequence(int n) that returns an array of 0..n in random order

rachel_m wrote:

I tried what you suggested and that did not work.

rachel_m wrote:

do you have any other suggestions?

Bastard Programmer from Hell
if you can't read my code, try converting it here[^]

yaswanth001 wrote:

Plz send me its urgent

yaswanth001 wrote:

I am getting ora-01036 oracle exception that is,illegal variable name/number