2019-09-11

0294.翻转游戏II/0294-翻转游戏II.py

@@ -0,0 +1,19 @@
+class Solution(object):
+    def canWin(self, string):
+        """
+        :type s: str
+        :rtype: bool
+        """
+        record = {}
+        def helper(s):
+            if s in record:
+                return record[s]
+            for i in range(len(s) - 1):
+                if s[i:i + 2] == "++":
+                    next_s = s[:i] + "--" + s[i + 2:]
+                    if not helper(next_s):
+                        record[next_s] = False
+                        return True
+            return False # ++²»´æÔÚ
+
+        return helper(string)