Question

How can I rearrange an array if I know where to put each element in array without using temporary array?

I guess, This has something to do with cyclic permutation but I cannot figure out how they can be linked each other. Wiki page seems irrelevant to me(http://en.wikipedia.org/wiki/Cyclic_permutation)

Answer 1

If you know both where to put each element in the array, and also which element of the array belongs at a specific index, then you can use that information to optimise your rearrangement. Otherwise you can iterate over all the array elements exchanging them into the correct location until they are all correctly placed.

void permuteObjects(Object[] elements, int[] positions)
{
  for (int i = 0; i < elements.length; ++i) {
    while (positions[i] != i) {
      swapObjects(elements, i, positions[i]);
      swapIntegers(positions, i, positions[i]);
    }
  }
}