Four Integer

题目
Given four integers, make F(S) = abs(S[0]-S[1])+abs(S[1]-S[2])+abs(S[2]-S[3]) to be largest.

import java.util.Arrays;

public class FourInteger {
    public int[] Solution(int A, int B, int C, int D) {
        int[] rvalue = new int[4];
        rvalue[0] = A;
        rvalue[1] = B;
        rvalue[2] = C;
        rvalue[3] = D;

        // first sort
        Arrays.sort(rvalue);

        // make 3 swaps
        swap(rvalue, 0, 1);
        swap(rvalue, 2, 3);
        swap(rvalue, 0, 3);
        return rvalue;
    }

    private void swap(int[] array, int i, int j) {
        int tmp = array[i];
        array[i] = array[j];
        array[j] = tmp;
    }
}