Java 2017.9.11 杨浩宁作业

//P61 2.15

import java.util.Scanner;

public class test {
    public static void main(String[] args) {
        Scanner Hy=new Scanner(System.in);
        double x1,x2,y1,y2;
        System.out.println("请键入X1的值：");
        x1 = Double.valueOf(Hy.nextLine());
        System.out.println("请键入X2的值：");
        x2 = Double.valueOf(Hy.nextLine());
        System.out.println("请键入Y1的值：");
        y1 = Double.valueOf(Hy.nextLine());
        System.out.println("请键入Y2的值：");
        y2 = Double.valueOf(Hy.nextLine());
        System.out.println("两个点之间的距离是："+ Math.pow((Math.pow((x2 - x1),2)+Math.pow((y2 - y1),2)),0.5));

    }
}

//P60 2.6

import java.util.Scanner;

public class test {
    public static void main(String[] args) {
        Scanner Hy=new Scanner(System.in);
        String Hyper;
        System.out.println("请输入一个0-1000的整数来求整数各位数的和");
        Hyper = Hy.nextLine();
        //方法1
        int test = Integer.valueOf(Hyper);
        if(test > 0 && test <= 1000) {
            int a = test % 2;
            int b = test / 10;
            int c = test / 100;
            System.out.println("总和为：" + (a + b + c));
        }
        else {
            System.out.println("不要皮！");
        }

        //方法2
        /*
        if(Integer.valueOf(Hyper) <= 1000) {
            int a = 0;
            for (int i = 0; i < Hyper.length(); i++) {
                a = a + Integer.valueOf(Hyper.substring(i, i + 1));
            }
            System.out.println(a);
        }*/

    }
}