第二章作业.

2.6

import java.util.Scanner;
　　public class Red{
　　public static void main(String[] args){
　　Scanner input =new Scanner(System.in);
　　System.out.println("Enter a number between 0 and 1000: ");
　　int number=input.nextInt();
　　int x,y,z,sun;
　　x=number/100;
　　y=(number%100)/10;
　　z=(number%100)%10;
　　sun=x+y+z;
　　System.out.println("the sun of the digits is" +sun);
　}
}

2.15

import java.util.Scanner;
public class ComputeDistance{
　　public static void main(String[] args){
　　double number;
　　Scanner input =new Scanner(System.in);
　　System.out.print("Enter x1 and y1:");
　　double x1 =input.nextDouble();
　　double y1 =input.nextDouble();
　　System.out.print("Enter x2 and y2:");
　　double x2 =input.nextDouble();
　　double y2 =input.nextDouble();
　　number =(x2-x1)*(x2-x1)+(y2-y1)*(y2-y1);
　　double distance =Math.pow(number,0.5);
　　System.out.println("the distance between the two points is" +distance);
　}
}