P5735 【深基7.例1】距离函数
import java.util.Scanner;//定义点类
class Point {public double x;public double y;public Point() {super();}public Point(double x, double y) {super();this.x = x;this.y = y;}public double getDis(Point p) {double dis;dis = Math.sqrt((x - p.x) * (x - p.x) + (y - p.y) * (y - p.y));return dis;}}//三角形类class Triangle{public Point a;public Point b;public Point c;public Triangle() {super();}public Triangle(Point a, Point b, Point c) {super();this.a = a;this.b = b;this.c = c;}public double getPerimeter() {double sum =0;sum+=a.getDis(b);sum+=b.getDis(c);sum+=c.getDis(a);return sum;}}//主类，必须是public
public class Main {public static void main(String[] args) {// TODO Auto-generated method stubScanner sc=new Scanner(System.in);Point p1= new Point(sc.nextDouble(),sc.nextDouble());Point p2= new Point(sc.nextDouble(),sc.nextDouble());Point p3= new Point(sc.nextDouble(),sc.nextDouble());sc.close();Triangle t1= new Triangle(p1,p2,p3);System.out.printf("%.2f", t1.getPerimeter());}}
