Given a list of 24-hour clock time points in "Hour:Minutes" format, find the minimum minutes difference between any two time points in the list. 
Example 1:
Input: ["23:59","00:00"]
Output: 1
Note:
The number of time points in the given list is at least 2 and won't exceed 20000.
The input time is legal and ranges from 00:00 to 23:59.
class Solution:
     def findMinDifference(self, timePoints):
         """
         :type timePoints: List[str]
         :rtype: int
         """
         def cv2mnt(t):
             h,m = t.split(':')
             mnt = int(h) * 60 + int(m)
             return mnt
         lst = [0 for i in range(1440)]
         for t in timePoints:
             mnt = cv2mnt(t)
             if lst[mnt] == 1:
                 return 0
             else:
                 lst[mnt] = 1
         beg = 0
         stk = [i for i,n in enumerate(lst) if n == 1]
         stk.append(stk[0] + 1440)
         res = 1439
         for i in range(len(stk) - 1):
             dif = abs(stk[i] - stk[i+1])
             dif_ = min(1440 - dif, dif)
             res = min(res,dif_)
             if res == 1:
                 return 1
         return res

class Solution:
     def findMinDifference(self, timePoints):
         """
         :type timePoints: List[str]
         :rtype: int
         """
         def cv2mnt(t):
             h,m = t.split(':')
             mnt = int(h) * 60 + int(m)
             return mnt
         lst = [0 for i in range(1440)]
         for t in timePoints:
             mnt = cv2mnt(t)
             if lst[mnt] == 1:
                 return 0
             else:
                 lst[mnt] = 1
         beg = 0
         stk = [i for i,n in enumerate(lst) if n == 1]
         stk.append(stk[0] + 1440)
         res = 1439
         for i in range(len(stk) - 1):
             dif = abs(stk[i] - stk[i+1])
             dif_ = min(1440 - dif, dif)
             res = min(res,dif_)
             if res == 1:
                 return 1
         return res
