// Marty Stepp, CSE 142, Spring 2010
// This program shows methods to swap elements in an array,
// and to swap the contents of two entire arrays.
// Its purpose is to demonstrate array parameters and reference semantics.

import java.util.*;

public class SwapAll {
    public static void main(String[] args) {
        int[] a1 = {12, 34, 56};
        swap(a1, 1, 2);
        System.out.println(Arrays.toString(a1));  // [12, 56, 34]
        swap(a1, 0, 2);
        System.out.println(Arrays.toString(a1));  //
        swap(a1, 1, 0);
        System.out.println(Arrays.toString(a1));  //
        System.out.println();
        
        int[] a3 = {12, 34, 56};
        int[] a4 = {20, 50, 80};
        swapAll(a3, a4);
        System.out.println(Arrays.toString(a3));  // [20, 50, 80]
        System.out.println(Arrays.toString(a4));  // [12, 34, 56]
    }
    
    public static void swapAll(int[] a1, int[] a2) {
        for (int i = 0; i < a1.length; i++) {
            int temp = a1[i];
            a1[i] = a2[i];
            a2[i] = temp;
        }
    }
    
    public static void swap(int[] a, int index1, int index2) {
        int temp = a[index1];
        a[index1] = a[index2];
        a[index2] = temp;
    }
}