Initial data commit

Task/Fibonacci-word/Java/fibonacci-word.java

@@ -0,0 +1,50 @@
+import java.util.*;
+
+public class FWord {
+    private /*v*/ String fWord0 = "";
+    private /*v*/ String fWord1 = "";
+
+    private String nextFWord () {
+        final String result;
+
+        if ( "".equals ( fWord1 ) )      result = "1";
+        else if ( "".equals ( fWord0 ) ) result = "0";
+        else                             result = fWord1 + fWord0;
+
+        fWord0 = fWord1;
+        fWord1 = result;
+
+        return result;
+    }
+
+    public static double entropy ( final String source ) {
+        final int                        length = source.length ();
+        final Map < Character, Integer > counts = new HashMap < Character, Integer > ();
+        /*v*/ double                     result = 0.0;
+
+        for ( int i = 0; i < length; i++ ) {
+            final char c = source.charAt ( i );
+
+            if ( counts.containsKey ( c ) ) counts.put ( c, counts.get ( c ) + 1 );
+            else                            counts.put ( c, 1 );
+        }
+
+        for ( final int count : counts.values () ) {
+            final double proportion = ( double ) count / length;
+
+            result -= proportion * ( Math.log ( proportion ) / Math.log ( 2 ) );
+        }
+
+        return result;
+    }
+
+    public static void main ( final String [] args ) {
+        final FWord fWord = new FWord ();
+
+        for ( int i = 0; i < 37;  ) {
+            final String word = fWord.nextFWord ();
+
+            System.out.printf ( "%3d %10d %s %n", ++i, word.length (), entropy ( word ) );
+        }
+    }
+}