Update snapshot-array.py

Author: kamyu104

Python/snapshot-array.py

@@ -12,7 +12,7 @@ def __init__(self, length):
         """
         :type length: int
         """
-        self.__A = collections.defaultdict(lambda: [(-1, 0)])
+        self.__A = collections.defaultdict(lambda: [[0, 0]])
         self.__snap_id = 0
 
 
@@ -22,7 +22,10 @@ def set(self, index, val):
         :type val: int
         :rtype: None
         """
-        self.__A[index].append((self.__snap_id, val))
+        if self.__A[index][-1][0] == self.__snap_id:
+            self.__A[index][-1][1] = val
+        else:
+            self.__A[index].append([self.__snap_id, val])
 
 
     def snap(self):
@@ -39,5 +42,5 @@ def get(self, index, snap_id):
         :type snap_id: int
         :rtype: int
         """
-        i = bisect.bisect_right(self.__A[index], (snap_id+1, 0)) - 1
+        i = bisect.bisect_left(self.__A[index], [snap_id+1, float("-inf")]) - 1
         return self.__A[index][i][1]