Create design-phone-directory.py

kamyu104 · web-flow · commit 460e31e3ece2 · 2016-08-03T22:52:54.000+08:00
diff --git a/Python/design-phone-directory.py b/Python/design-phone-directory.py
@@ -0,0 +1,61 @@
+# init:     Time: O(n), Space: O(n)
+# get:      Time: O(1), Space: O(1)
+# check:    Time: O(1), Space: O(1)
+# release:  Time: O(1), Space: O(1)
+
+class PhoneDirectory(object):
+
+    def __init__(self, maxNumbers):
+        """
+        Initialize your data structure here
+        @param maxNumbers - The maximum numbers that can be stored in the phone directory.
+        :type maxNumbers: int
+        """
+        self.__curr = 0
+        self.__numbers = range(maxNumbers)
+        self.__used = [False] * maxNumbers
+
+
+    def get(self):
+        """
+        Provide a number which is not assigned to anyone.
+        @return - Return an available number. Return -1 if none is available.
+        :rtype: int
+        """
+        if self.__curr == len(self.__numbers):
+            return -1
+        number = self.__numbers[self.__curr]
+        self.__curr += 1
+        self.__used[number] = True
+        return number
+        
+
+    def check(self, number):
+        """
+        Check if a number is available or not.
+        :type number: int
+        :rtype: bool
+        """
+        return 0 <= number < len(self.__numbers) and \
+               not self.__used[number]
+        
+
+    def release(self, number):
+        """
+        Recycle or release a number.
+        :type number: int
+        :rtype: void
+        """
+        if not 0 <= number < len(self.__numbers) or \
+           not self.__used[number]:
+            return
+        self.__used[number] = False
+        self.__curr -= 1
+        self.__numbers[self.__curr] = number
+        
+
+# Your PhoneDirectory object will be instantiated and called as such:
+# obj = PhoneDirectory(maxNumbers)
+# param_1 = obj.get()
+# param_2 = obj.check(number)
+# obj.release(number)
