import java.util.Scanner;
public class Ex {
public static void main(String[] args) {
Scanner Lf=new Scanner(System.in);
double x1,x2,y1,y2;
System.out.println("请键入X1的值:");
x1 = Double.valueOf(Lf.nextLine());
System.out.println("请键入X2的值:");
x2 = Double.valueOf(Lf.nextLine());
System.out.println("请键入Y1的值:");
y1 = Double.valueOf(Lf.nextLine());
System.out.println("请键入Y2的值:");
y2 = Double.valueOf(Lf.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));
}
}