package algs11;
import stdlib.*;

public class XSwap {
  public static void main (String[] args) {
    {
      int x = 42;
      int y = 27;
      StdOut.format ("before x=%d y=%d\n" , x, y);
      swap1 (x, y);
      StdOut.format ("after  x=%d y=%d\n\n" , x, y);
    }
    {
      Integer x = Integer.valueOf (42);
      Integer y = Integer.valueOf (27);
      StdOut.format ("before x=%d y=%d\n" , x, y);
      swap2 (x, y);
      StdOut.format ("after  x=%d y=%d\n\n" , x, y);
    }
    {
      int[] a = new int[2];
      a[0] = 42;
      a[1] = 27;
      StdOut.format ("before x=%d y=%d\n" , a[0], a[1]);
      swap3 (a, 0, 1);
      StdOut.format ("after  x=%d y=%d\n\n" , a[0], a[1]);
    }
    {
      Integer[] a = new Integer[2];
      a[0] = Integer.valueOf (42);
      a[1] = Integer.valueOf (27);
      StdOut.format ("before x=%d y=%d\n" , a[0], a[1]);
      swap4 (a, 0, 1);
      StdOut.format ("after  x=%d y=%d\n\n" , a[0], a[1]);
    }
  }
  static void swap1 (int a, int b) {
    int t = a;
    a = b;
    b = t;
  }
  static void swap2 (Integer a, Integer b) {
    Integer t = a;
    a = b;
    b = t;
  }
  static void swap3 (int[] a, int i, int j) {
    int t = a[i];
    a[i] = a[j];
    a[j] = t;
  }
  static void swap4 (Object[] a, int i, int j) {
    Object t = a[i];
    a[i] = a[j];
    a[j] = t;
  }
}