add LindenmayerSystemSnippet & tests and Update README.md

README.md

@@ -1915,6 +1915,44 @@ public class LevenshteinDistanceSnippet {
 }
 ```
 
+### Lindenmayer System 
+
+```java
+public class LindenmayerSystemSnippet {
+  /**
+   * Generates an L-system string based on axiom, production rules, and a number of iterations.
+   *
+   * @param axiom           initial string to begin the L-system
+   * @param productionRules map of character rules where each symbol can be replaced with a string
+   * @param iterations      number of iterations to apply the production rules
+   * @return the generated string after all iterations
+   */
+  public static String generateLindenmayerSystem(
+          String axiom,
+          Map<Character, String> productionRules,
+          int iterations
+  ) {
+    String current = axiom;
+
+    for (int i = 0; i < iterations; i++) {
+      StringBuilder nextIteration = new StringBuilder(current.length() * 2);
+
+      // Replace each symbol with the corresponding production rule or the symbol itself
+      current.chars()
+          .mapToObj(c -> (char) c)
+          .forEach(symbol ->
+                  nextIteration.append(
+                          productionRules.getOrDefault(symbol, String.valueOf(symbol))
+                  )
+          );
+
+      current = nextIteration.toString();
+    }
+    return current;
+  }
+}
+```
+
 ### Max Character Count
 
 ```java

src/main/java/string/LindenmayerSystemSnippet.java

@@ -0,0 +1,64 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017-2024 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package string;
+
+import java.util.Map;
+
+/**
+ * LSystemSnippet.
+ */
+public class LindenmayerSystemSnippet {
+  /**
+   * Generates an L-system string based on axiom, production rules, and a number of iterations.
+   *
+   * @param axiom           initial string to begin the L-system
+   * @param productionRules map of character rules where each symbol can be replaced with a string
+   * @param iterations      number of iterations to apply the production rules
+   * @return the generated string after all iterations
+   */
+  public static String generateLindenmayerSystem(
+          String axiom,
+          Map<Character, String> productionRules,
+          int iterations
+  ) {
+    String current = axiom;
+
+    for (int i = 0; i < iterations; i++) {
+      StringBuilder nextIteration = new StringBuilder(current.length() * 2);
+
+      // Replace each symbol with the corresponding production rule or the symbol itself
+      current.chars()
+          .mapToObj(c -> (char) c)
+          .forEach(symbol ->
+                  nextIteration.append(
+                          productionRules.getOrDefault(symbol, String.valueOf(symbol))
+                  )
+          );
+
+      current = nextIteration.toString();
+    }
+    return current;
+  }
+}

src/test/java/string/LindenmayerSystemSnippetTest.java

@@ -0,0 +1,70 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017-2024 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package string;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.HashMap;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+
+
+/*
+ * Tests for 30 Seconds of Java code library
+ *
+ */
+class LindenmayerSystemSnippetTest {
+
+  /**
+   * Tests for {@link LindenmayerSystemSnippet#generateLindenmayerSystem(String, Map, int)}.
+   */
+  @Test
+  public void testGenerateLindenmayerSystems() {
+    String axiom = "A";
+
+
+    Map<Character, String> productionRules = new HashMap<>();
+    productionRules.put('A', "AB");
+    productionRules.put('B', "A");
+
+
+    assertEquals(
+        "AB",
+        LindenmayerSystemSnippet.generateLindenmayerSystem(axiom, productionRules, 1)
+    );
+    assertEquals(
+        "ABA",
+        LindenmayerSystemSnippet.generateLindenmayerSystem(axiom, productionRules, 2)
+    );
+    assertEquals(
+        "ABAAB",
+        LindenmayerSystemSnippet.generateLindenmayerSystem(axiom, productionRules, 3)
+    );
+    assertEquals(
+        axiom,
+        LindenmayerSystemSnippet.generateLindenmayerSystem(axiom, productionRules, 0)
+    );
+  }
+}