Add LCMServer class

app/src/main/java/ch/nuth/zhaw/exbox/LCMServer.java

@@ -0,0 +1,40 @@
+package ch.nuth.zhaw.exbox;
+
+import java.util.Formatter;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class LCMServer implements CommandExecutor {
+    Formatter formatter = new Formatter();
+    Pattern pattern = Pattern.compile("^([0-9]+),?\\s*([0-9]+)$");
+
+    @Override
+    public String execute(String command) throws Exception {
+        Matcher matcher = pattern.matcher(command);
+
+        if (matcher.find()) {
+            int x = Integer.parseInt(matcher.group(1));
+            int y = Integer.parseInt(matcher.group(2));
+            int result = leastCommonMultiple(x, y);
+            return "Das Resultat ist %d\n".formatted(result);
+        }
+        else {
+            throw new Exception("Der angegebene Befehl \"%s\" ist ungültig!\n".formatted(command));
+        }
+    }
+
+    public int leastCommonMultiple(int x, int y) {
+        return Math.abs(x * y) / greatestCommonDivisor(x, y);
+    }
+
+    public int greatestCommonDivisor(int x, int y) {
+        while (y != 0) {
+            x %= y;
+            x ^= y;
+            y ^=x;
+            x ^= y;
+        }
+
+        return x;
+    }
+}