利用两数之和实现两个数交换（java版本）

• 简单说明
  

import java.util.Scanner;
public class HelloWorld {
    public static void main(String[] args) {
        int num1 = 23;
        int num2 = 24;
        System.out.println("num1: " + num1);
        System.out.println("num2: " + num2);
        num1 = num1 + num2; // num1为两数之和
        num2 = num1 - num2;
        num1 = num1 - num2;
        System.out.println("改变后num1: " + num1);
        System.out.println("改变后num2: " + num2);
    }
}

• 可输入版本

import java.util.Scanner;
public class HelloWorld {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("输入num1: " );
        int num1 = sc.nextInt();
        System.out.println("输入num2: " );
        int num2 = sc.nextInt();
        System.out.println("num1: " + num1);
        System.out.println("num2: " + num2);
        num1 = num1 + num2; // num1为两数之和
        num2 = num1 - num2;
        num1 = num1 - num2;
        System.out.println("改变后num1: " + num1);
        System.out.println("改变后num2: " + num2);
    }
}