Add distance between two points algorithm (#7218)

* Add distance between two points algorithm

* Create DistanceBetweenTwoPointsTest.java

* DistanceBetweenTwoPoints.java

* Fix test file package and project structure

* Delete src/test/java/com/thealgorithms/DistanceBetweenTwoPointsTest.java

* Apply clang-format compliant formatting

* Apply clang-format

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Co-authored-by: a <19151554+alxkm@users.noreply.github.com>

src/main/java/com/thealgorithms/maths/DistanceBetweenTwoPoints.java

@@ -0,0 +1,33 @@
+package com.thealgorithms.maths;
+
+/**
+ * Distance Between Two Points in 2D Space.
+ *
+ * <p>This class provides a method to calculate the Euclidean distance between two points in a
+ * two-dimensional plane.
+ *
+ * <p>Formula: d = sqrt((x2 - x1)^2 + (y2 - y1)^2)
+ *
+ * <p>Reference: https://en.wikipedia.org/wiki/Euclidean_distance
+ */
+public final class DistanceBetweenTwoPoints {
+
+    private DistanceBetweenTwoPoints() {
+        // Utility class; prevent instantiation
+    }
+
+    /**
+     * Calculate the Euclidean distance between two points.
+     *
+     * @param x1 x-coordinate of the first point
+     * @param y1 y-coordinate of the first point
+     * @param x2 x-coordinate of the second point
+     * @param y2 y-coordinate of the second point
+     * @return Euclidean distance between the two points
+     */
+    public static double calculate(final double x1, final double y1, final double x2, final double y2) {
+        final double deltaX = x2 - x1;
+        final double deltaY = y2 - y1;
+        return Math.sqrt(deltaX * deltaX + deltaY * deltaY);
+    }
+}

src/test/java/com/thealgorithms/maths/DistanceBetweenTwoPointsTest.java

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+package com.thealgorithms.maths;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class DistanceBetweenTwoPointsTest {
+
+    @Test
+    void testDistanceSimple() {
+        assertEquals(5.0, DistanceBetweenTwoPoints.calculate(0, 0, 3, 4), 1e-9);
+    }
+
+    @Test
+    void testDistanceNegativeCoordinates() {
+        assertEquals(5.0, DistanceBetweenTwoPoints.calculate(-1, -1, 2, 3), 1e-9);
+    }
+
+    @Test
+    void testSamePoint() {
+        assertEquals(0.0, DistanceBetweenTwoPoints.calculate(2, 2, 2, 2), 1e-9);
+    }
+}