Switching a elements in char array to the corresponding positions in an int array java

javabeginner :

I'm trying to switch the elements in the letters array to the corresponding positions in the positions array. The elements are getting swapped but not to the right position. Am I doing this completely wrong or is there just a problem in my logic?

public class Words
{
    public static void main (String args[])
    {
        char letters[] = {'l', 'o', 'e', 'h', 'l'};
        int positions[] = {2, 4, 1, 0, 3};

        int limit1 = letters.length;
        int temp1;
        char temp2;
        for(int i = 0; i < letters.length; i++)
        {
            limit1--;
            for(int j = 0; j < limit1; j++)
            {
                temp1 = positions[j];
                temp2 = letters[temp1];
                letters[temp1] = letters[j];
                letters[j] = temp2;
            }
        }
        for(int i = 0; i < letters.length; i++)
        {
            System.out.print(letters[i] + " ");
        }
    }
}

Andreas :

If you don't have to do this in-place, it would be a lot easier to just create a new array.

char[] letters = {'l', 'o', 'e', 'h', 'l'};
int[] positions = {2, 4, 1, 0, 3};

char[] result = new char[letters.length];
for (int i = 0; i < letters.length; i++)
    result[positions[i]] = letters[i];

System.out.println(result);

Output

hello

For an in-place solution, the following will do. Same output as above.

char letters[] = {'l', 'o', 'e', 'h', 'l'};
int positions[] = {2, 4, 1, 0, 3};

for (int i = 0, j; i < letters.length; i++) {
    while ((j = positions[i]) != i) {
        char tempLetter = letters[i];
        letters[i] = letters[j];
        letters[j] = tempLetter;
        int tempPosition = positions[i];
        positions[i] = positions[j];
        positions[j] = tempPosition;
    }
}

System.out.println(letters);

That can easily be written using only one loop.

for (int i = 0, j; i < letters.length; ) {
    if ((j = positions[i]) == i) {
        i++;
    } else {
        char tempLetter = letters[i];
        letters[i] = letters[j];
        letters[j] = tempLetter;
        int tempPosition = positions[i];
        positions[i] = positions[j];
        positions[j] = tempPosition;
    }
}