兩值互換的三種方法

兩值互換的3種方法

一、最簡單的一種想法，求和相減法

public class 兩值交換01 {
    @SuppressWarnings("resource")
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int num01 = input.nextInt();
        int num02 = input.nextInt();
        System.out.println("數值互換前");
        System.out.println("num01=" + num01 + "," + "num02=" + num02);
        num01=num01+num02;//num01(15)=num01(10)+num02(5)
        num02=num01-num02;//num02(10)=num01(15)-num02(5)
        num01=num01-num02;//num01(5)=num01(15)-num02(10)
        System.out.println("數值互換後");
        System.out.println("num01=" + num01 + "," + "num02=" + num02);
    }
}

效果圖

二、最經常使用方法，利用中間值

public class 兩值交換02 {
    @SuppressWarnings("resource")
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int num01 = input.nextInt();
        int num02 = input.nextInt();
        System.out.println("數值互換前");
        System.out.println("num01=" + num01 + "," + "num02=" + num02);
        int temp;
        temp = num01;
        num01 = num02;
        num02 = temp;
        System.out.println("數值互換後");
        System.out.println("num01=" + num01 + "," + "num02=" + num02);
    }
}

效果圖

三、利用異或運算

public class 兩值交換03 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int num01 = input.nextInt();
        int num02 = input.nextInt();
        System.out.println("數值互換前");
        System.out.println("num01=" + num01 + "," + "num02=" + num02);
        num01 = num01 ^ num02;
        num02 = num01 ^ num02;
        num01 = num01 ^ num02;
        System.out.println("數值互換後");
        System.out.println("num01=" + num01 + "," + "num02=" + num02);
    }
}

效果圖

若不理解異或概念，請先看看如下內容
http://blog.csdn.net/renjie_9...
http://www.cnblogs.com/Rachel...