# Java: Test if circumference of two circles intersect or overlap

## Java Basic: Exercise-224 with Solution

There are two circles C1 with radius r1, central coordinate (x1, y1) and C2 with radius r2 and central coordinate (x2, y2).
Write a Java program to test the followings -
"C2 is in C1" if C2 is in C1
"C1 is in C2" if C1 is in C2
"Circumference of C1 and C2 intersect" if circumference of C1 and C2 intersect, and
"C1 and C2 do not overlap" if C1 and C2 do not overlap.

Input:
Input numbers (real numbers) are separated by a space.

Visual Presentation: Sample Solution:

Java Code:

``````// Importing the Scanner class for user input
import java.util.Scanner;

// Main class named "Main"
public class Main {
// Main method to execute the program
public static void main(String arg[]) {
// Creating a Scanner object for user input
Scanner in = new Scanner(System.in);

// Prompting the user to input x1, y1, and r1 for the first circle
System.out.println("Input x1, y1, r1: (numbers are separated by a space)");
double x1 = in.nextDouble(), y1 = in.nextDouble(), r1 = in.nextDouble();

// Prompting the user to input x2, y2, and r2 for the second circle
System.out.println("Input x2, y2, r2: (numbers are separated by a space)");
double x2 = in.nextDouble(), y2 = in.nextDouble(), r2 = in.nextDouble();

// Calculating the distance between the centers of the two circles
double l = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));

// Checking the relationship between the circles based on their radii and distance
if (l > r1 + r2)
System.out.println("Circumference of C1 and C2 intersect");
else if (r1 > l + r2)
System.out.println("C2 is in C1");
else if (r2 > l + r1)
System.out.println("C1 is in C2");
else
System.out.println("C1 and C2 do not overlap");
}
}
```
```

Sample Output:

```Input x1, y1, r1: (numbers are separated by a space)
5 6 8 7
Input x2, y2, r2: (numbers are separated by a space)
8 9 5 4
C1 and C2  do not overlap
```

Flowchart: Java Code Editor: