refactor 464

fishercoder1534 · fishercoder1534 · commit 4b84d487b4d7 · 2019-04-24T07:29:23.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_464.java b/src/main/java/com/fishercoder/solutions/_464.java
@@ -30,59 +30,62 @@
  Same with other integers chosen by the first player, the second player will always win.
  */
 public class _464 {
-    /**Credit: https://discuss.leetcode.com/topic/68896/java-solution-using-hashmap-with-detailed-explanation*/
+    public static class Solution1 {
+        /**
+         * Credit: https://discuss.leetcode.com/topic/68896/java-solution-using-hashmap-with-detailed-explanation
+         */
 
-    Map<Integer, Boolean> map;
-    boolean[] used;
+        Map<Integer, Boolean> map;
+        boolean[] used;
 
-    public boolean canIWin(int maxChoosableInteger, int desiredTotal) {
-        int sum = (1 + maxChoosableInteger) * maxChoosableInteger / 2;
-        if (sum < desiredTotal) {
-            return false;
-        }
-        if (desiredTotal <= 0) {
-            return true;
-        }
-
-        map = new HashMap();
-        used = new boolean[maxChoosableInteger + 1];
-        return helper(desiredTotal);
-    }
+        public boolean canIWin(int maxChoosableInteger, int desiredTotal) {
+            int sum = (1 + maxChoosableInteger) * maxChoosableInteger / 2;
+            if (sum < desiredTotal) {
+                return false;
+            }
+            if (desiredTotal <= 0) {
+                return true;
+            }
 
-    public boolean helper(int desiredTotal) {
-        if (desiredTotal <= 0) {
-            return false;
+            map = new HashMap();
+            used = new boolean[maxChoosableInteger + 1];
+            return helper(desiredTotal);
         }
-        int key = format(used);
-        if (!map.containsKey(key)) {
-            // try every unchosen number as next step
-            for (int i = 1; i < used.length; i++) {
-                if (!used[i]) {
-                    used[i] = true;
-                    // check whether this lead to a win (i.e. the other player lose)
-                    if (!helper(desiredTotal - i)) {
-                        map.put(key, true);
+
+        public boolean helper(int desiredTotal) {
+            if (desiredTotal <= 0) {
+                return false;
+            }
+            int key = format(used);
+            if (!map.containsKey(key)) {
+                // try every unchosen number as next step
+                for (int i = 1; i < used.length; i++) {
+                    if (!used[i]) {
+                        used[i] = true;
+                        // check whether this lead to a win (i.e. the other player lose)
+                        if (!helper(desiredTotal - i)) {
+                            map.put(key, true);
+                            used[i] = false;
+                            return true;
+                        }
                         used[i] = false;
-                        return true;
                     }
-                    used[i] = false;
                 }
+                map.put(key, false);
             }
-            map.put(key, false);
+            return map.get(key);
         }
-        return map.get(key);
-    }
 
-    // transfer boolean[] to an Integer
-    public int format(boolean[] used) {
-        int num = 0;
-        for (boolean b : used) {
-            num <<= 1;
-            if (b) {
-                num |= 1;
+        // transfer boolean[] to an Integer
+        public int format(boolean[] used) {
+            int num = 0;
+            for (boolean b : used) {
+                num <<= 1;
+                if (b) {
+                    num |= 1;
+                }
             }
+            return num;
         }
-        return num;
     }
-
 }
