判断数字的奇偶性+判断俩个数大小+判断三个数大小+不改变三个数的内容将三个数排序

范例：
//判断数字的奇偶性
System.out.println("请输入一个数");
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
        if (num%2==0){
            System.out.println(num + "是偶数");
        }else {
            System.out.println(num + "是奇数");
        }
//判断俩个数的大小
        System.out.println("请输入俩个数字");
        Scanner num1 = new Scanner(System.in);
        Scanner num2 = new Scanner(System.in);
        int a = num1.nextInt();
        int b = num2.nextInt();

        if (a - b == 0){
                System.out.println("a=b");
            }else if(a - b > 0){
            System.out.println("a>b");
        }else {
            System.out.println("a<b");
        }
//        判断三个数的大小
        int a , b ,c, max;
        System.out.println("请输入三个整数");
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    b = sc.nextInt();
    c = sc.nextInt();
    max = a;
    if (b > max) max = b;
    if (c > max) max = c;
        System.out.println("max =" + max );
  int a , b , c ,r;
        System.out.println("请输入三个整数");
        Scanner sc = new Scanner(System.in);
        a = sc.nextInt();
        b = sc.nextInt();
        c = sc.nextInt();
//    对三个数由小到大排序，不改变三个数的内容
        int a, b, c;
        System.out.println("请输入三个整数");
        Scanner sc = new Scanner(System.in);
        a = sc.nextInt();
        b = sc.nextInt();
        c = sc.nextInt();
        if (a > b) {

            if (b > c) {
                System.out.println("a>b>c");
            } else {
                System.out.println("a>c>b");
            }
        } else {
            if (c < a) {
                System.out.println("b>a>c");
            } else {
                if (c > b) {
                    System.out.println("c>b>a");
                } else {
                    System.out.println("b>c>a");
                }
            }
        }

//选出ab中较小的数
        if (a>b) {
            r = a;
            a = b;
            b = r;
        }
        //选出ac中较小的数
        if (a>c) {
            r = a;
            a = c;
            c = r;
        }
        //选出bc中较小的数
        if (b>c) {
            r = b;
            b = c;
            c = r;
        }
        System.out.println(a+"<"+b+"<"+c);