Data update

Task/Tree-datastructures/Java/tree-datastructures.java

@@ -0,0 +1,57 @@
+public class TreeDatastructures {
+
+	public static void main(String[] args) {
+		String initialNested = """
+	    Rosetta Code
+	    ....rocks
+	    ........code
+	    ........comparison
+	    ........wiki
+	    ....mocks
+	    ........trolling
+	    """;
+	
+	    System.out.println(initialNested);
+	
+	    String indented = nestedToIndented(initialNested);
+	    System.out.println(indented);
+	
+	    String finalNested = indentedToNested(indented);
+	    System.out.println(finalNested);
+
+	    final boolean equal = ( initialNested.compareTo(finalNested) == 0 );
+	    System.out.println("initialNested = finalNested ? " + equal);
+	}	
+	
+	private static String nestedToIndented(String nested) {
+		StringBuilder result = new StringBuilder();
+	
+		for ( String line : nested.split(LINE_END) ) {
+			int index = 0;
+			while ( line.charAt(index) == '.' ) {
+				index += 1;
+			}						
+			result.append(String.valueOf(index / 4) + " " + line.substring(index) + LINE_END);			
+		}
+		
+		return result.toString();
+	}	
+
+	private static String indentedToNested(String indented) {
+		StringBuilder result = new StringBuilder();
+		
+		for ( String line : indented.split(LINE_END) ) {
+			final int index = line.indexOf(' ');
+			final int level = Integer.valueOf(line.substring(0, index));			
+			for ( int i = 0; i < level; i++ ) {
+				result.append("....");
+			}
+			result.append(line.substring(index + 1) + LINE_END);
+		}		
+		
+		return result.toString();
+	}
+	
+	private static final String LINE_END = "\n";
+
+}