new tasks

Task/Best_shuffle/Java/best_shuffle.java

@@ -0,0 +1,36 @@
+import java.util.*;
+
+public class BestShuffle {
+
+    public static void main(String[] args) {
+        String[] words = {"abracadabra", "seesaw", "grrrrrr", "pop", "up", "a"};
+        for (String w : words)
+            System.out.println(bestShuffle(w));
+    }
+
+    public static String bestShuffle(final String s1) {
+        char[] s2 = s1.toCharArray();
+        Collections.shuffle(Arrays.asList(s2));
+        for (int i = 0; i < s2.length; i++) {
+            if (s2[i] != s1.charAt(i))
+                continue;
+            for (int j = 0; j < s2.length; j++) {
+                if (s2[i] != s2[j] && s2[i] != s1.charAt(j) && s2[j] != s1.charAt(i)) {
+                    char tmp = s2[i];
+                    s2[i] = s2[j];
+                    s2[j] = tmp;
+                    break;
+                }
+            }
+        }
+        return s1 + " " + new String(s2) + " (" + count(s1, s2) + ")";
+    }
+
+    private static int count(final String s1, final char[] s2) {
+        int count = 0;
+        for (int i = 0; i < s2.length; i++)
+            if (s1.charAt(i) == s2[i])
+                count++;
+        return count;
+    }
+}