Add Goldbach's Conjecture algorithm (#6127)

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

@@ -0,0 +1,30 @@
+package com.thealgorithms.maths;
+
+import static com.thealgorithms.maths.PrimeCheck.isPrime;
+
+/**
+ * This is a representation of the unsolved problem of Goldbach's Projection, according to which every
+ * even natural number greater than 2 can be written as the sum of 2 prime numbers
+ * More info: https://en.wikipedia.org/wiki/Goldbach%27s_conjecture
+ * @author Vasilis Sarantidis (https://github.com/BILLSARAN)
+ */
+
+public final class GoldbachConjecture {
+    private GoldbachConjecture() {
+    }
+    public record Result(int number1, int number2) {
+    }
+
+    public static Result getPrimeSum(int number) {
+        if (number <= 2 || number % 2 != 0) {
+            throw new IllegalArgumentException("Number must be even and greater than 2.");
+        }
+
+        for (int i = 0; i <= number / 2; i++) {
+            if (isPrime(i) && isPrime(number - i)) {
+                return new Result(i, number - i);
+            }
+        }
+        throw new IllegalStateException("No valid prime sum found."); // Should not occur
+    }
+}