Add all 23 GoF design pattern implementations (2026-06-13)

02-structural/flyweight/Tree.java

@@ -0,0 +1,31 @@
+package flyweight;
+
+/**
+ * Context — stores the UNIQUE (extrinsic) state for each tree instance.
+ * This is NOT the flyweight itself; it's the lightweight object that
+ * holds position data and delegates rendering to a shared TreeType.
+ *
+ * 10,000 Tree objects × (x:4 bytes + y:4 bytes + reference:8 bytes) = ~160 KB
+ * vs.
+ * 10,000 Tree objects × (name + color + texture + x + y) = potentially MBs
+ */
+public class Tree {
+
+    // Extrinsic (unique) state — different per tree
+    private final int x;
+    private final int y;
+
+    // Reference to the SHARED flyweight
+    private final TreeType type;
+
+    public Tree(int x, int y, TreeType type) {
+        this.x    = x;
+        this.y    = y;
+        this.type = type;
+    }
+
+    public void draw() {
+        // Passes extrinsic state (position) into the shared flyweight
+        type.draw(x, y);
+    }
+}