OK, así que he escrito la mayor parte de un programa que me permitirá determinar si dos círculos se superponen.

No tengo ningún problema con mi programa aparte de un problema: el programa no aceptará el código que he escrito para la distancia entre los dos puntos centrales. Puedo averiguar la lógica if / else para decirle al usuario qué sucede dependiendo del valor de la distancia más adelante, pero quiero saber qué está mal ahora. Eclipse, el programa en el que estoy codificando, me dice que la distancia se debe resolver en una matriz, pero ya le dije que es un int.

Aquí está mi código:

package circles;
import java.util.Scanner;

public class MathCircles {

    // variable for the distance between the circles' centers
    public static int distance; 

    // variable for the lengths of the radii combined
    public static int radii;

     public static void main(String[] args) {
    // Get the x-value of the center of circle one
    System.out.println("What is the x-coordinate for the center of circle one?");
    Scanner keyboard = new Scanner(System.in);
    int x1 = keyboard.nextInt();

    //Get the y-value of the center of circle one
    System.out.println("What is the y-coordinate for the center of circle one?");
    Scanner keyboard1 = new Scanner(System.in);
    int y1 = keyboard1.nextInt(); 

    //Get the radius length of circle one.
    System.out.println("How long is circle one's radius?");
    Scanner keyboard2 = new Scanner(System.in);
    int r1 = keyboard2.nextInt();

 // Get the x-value of the center of circle two.
    System.out.println("What is the x-coordinate for the center of circle two?");
    Scanner keyboard3 = new Scanner(System.in);
    int x2 = keyboard3.nextInt();

  //Get the y-value of the center of circle two.
    System.out.println("What is the y-coordinate for the center of circle two?");
    Scanner keyboard4 = new Scanner(System.in);
    int y2 = keyboard4.nextInt(); 

   //Get the radius length of circle two.
    System.out.println("How long is circle two's radius?");
    Scanner keyboard5 = new Scanner(System.in);
    int r2 = keyboard5.nextInt();

/*
 * OK, so now I have the location of the two circles' centers,
    * as well as the lengths of their radii. 
    * The circles are intersecting IF THE DISTANCE BETWEEN THE TWO CENTERS
    * IS EQUAL TO OR LESS THAN THE COMBINED LENGTHS OF THE RADII.
    * Now I need to get some math done. 
    */

//calculate the combined lengths of the radii

radii = r1 + r2; 

//calculate the distance
distance = Math.sqrt((x1-x2)(x1-x2) + (y1-y2)(y1-y2));




}

}