Initial data commit

Task/Reverse-a-string/Java/reverse-a-string-3.java

@@ -0,0 +1,24 @@
+import java.text.BreakIterator;
+
+public class Reverse {
+  /* works with Java 20+ only
+   * cf. https://bugs.openjdk.org/browse/JDK-8291660
+   */
+  public static StringBuilder graphemeReverse(String text) {
+    BreakIterator boundary = BreakIterator.getCharacterInstance();
+    boundary.setText(text);
+    StringBuilder reversed = new StringBuilder();
+    int end = boundary.last();
+    int start = boundary.previous();
+    while (start != BreakIterator.DONE) {
+      reversed.append(text.substring(start, end));
+      end = start;
+      start = boundary.previous();
+    }
+    return reversed;
+  }
+  public static void main(String[] args) throws Exception {
+    String a = "as⃝df̅";
+    System.out.println(graphemeReverse(a)); // f̅ds⃝a
+  }
+}