circular left shift of an array by n positions in java

Question

I am trying to do the circular left shift of an array by n positions using only a single 1D array. I can do it in two arrays, but I haven\'t figured out how to do it using o

Answer 1

I would shift it 1 element at a time in place, using a single temporary variable to hold the element while moving elements 1 place along each. I would then repeat this n times to achieve n shifts.

public static void main( String[] args ) {
    int[] array = {1,2,3,4,5,6,7,8};
    leftShift( array, 3);
    System.out.println( Arrays.toString( array));
}

public static void leftShift(int[] array, int n) {
    for (int shift = 0; shift < n; shift++) {
        int first = array[0];
        System.arraycopy( array, 1, array, 0, array.length - 1 );
        array[array.length - 1] = first;
    }
}

Output:

[4, 5, 6, 7, 8, 1, 2, 3]

Not too inefficient, as System.arraycopy() is highly optimized.