repeatreverse.java

来自「Java 入门书的源码」· Java 代码 · 共 52 行

//Copyright (c) 1998, Arthur Gittleman
//This example is provided WITHOUT ANY WARRANTY either expressed or implied.

/*  Reverses an array.  The user inputs the
 *  size of the array and enters its components.
 */

import iopack.Io;         
public class RepeatReverse {
  public static int[] readIntArray() {
    int size = Io.readInt("Enter the array size");
    int [] anArray = new int[size];
    for (int i=0; i<size; i++)
      anArray[i] = Io.readInt("Enter anArray["+i+"]");
    return anArray;
  }
  public static void reverse(int [] anArray) {
    int temp;                       // used to store a value during a swap
    int left = 0;                   // index of the left element to swap
    int right = anArray.length -1;  // index of the right element to swap
    while (left < right) {
      temp           = anArray[left];
      anArray[left]  = anArray[right];
      anArray[right] = temp;
      right--;
      left++;
    } 
  }
  public static void display(int [] anArray) {                        
    System.out.print("{");
    for (int i=0; i<anArray.length; i++) { 
      if (i!=0) System.out.print(",");
        System.out.print(anArray[i]);
    }
    System.out.println("}");
  }
  public static void main(String [] args)  {
    char repeat;           // 'Y' to repeat, 'N' to quit
    int [] theArray;       // the array to reverse
    do {
      theArray = readIntArray();    
      System.out.print("The input array is ");
      display(theArray);
      reverse(theArray);
      System.out.print("The reversed array is "); 
      display(theArray);
      repeat = Io.readChar("Enter 'Y' to repeat, 'N' to quit");
    } while (repeat == 'Y' || repeat == 'y');
    Io.readString("Press any key to exit");   // Added for IDE use
  }                 
}