Python 3   ||  6 lines,  w/ example   ||   T/S: 91% / 96%
\nclass Solution:\n    def maximumSum(self, arr: List[int]) -> int:        #  Example: arr = [1,-2,5,-4,3]\n\n        mx = n0 = n1 = -inf                       
```\nclass Solution:\n    def maximumSum(self, arr: List[int]) -> int:        #  Example: arr = [1,-2,5,-4,3]\n\n        mx = n0 = n1 = -inf                             #   i    arr[:i+1]         n0    n1    mx\n                                                        #  \u2013\u2013\u2013   \u2013\u2013\u2013\u2013\u2013\u2013\u2013\u2013\u2013        \u2013\u2013\u2013\u2013  \u2013\u2013\u2013\u2013  \u2013\u2013\u2013\u2013  \n        for i, num in enumerate(arr):                   #                         -inf  -inf  -inf\n                                                        #   0    [1]                1   -inf    1\n            n1 = max(n0,  n1 + num)                     #   1    [1,-2]            -1     1     1\n            n0 = max(num, n0 + num)                     #   2    [1,-2, 5]          5     6     6\n            mx = max(mx,  n1,   n0)                     #   3    [1,-2, 5,-4]       1     5     6\n                                                        #   4    [1,-2, 5,-4, 3]    4     8     8\n        return mx\n```\n[https://leetcode.com/problems/maximum-subarray-sum-with-one-deletion/submissions/1274377210/](https://leetcode.com/problems/maximum-subarray-sum-with-one-deletion/submissions/1274377210/)\n\nI could be wrong, but I think that time is *O*(*N*) and space is *O*(1), in which *N* ~ `len(arr)`.
['Python', 'Python3']