[Python3] hash table
Please pull this commit for solutions of weekly 302. \n\n\nclass Solution:\n    def maximumSum(self, nums: List[int]) -> int:\n        ans = -1\n        seen = 
Please pull this [commit](https://github.com/gaosanyong/leetcode/commit/e6b38b5fa8ff313543c0b854e395b2eddc7e8c93) for solutions of weekly 302. \n\n```\nclass Solution:\n    def maximumSum(self, nums: List[int]) -> int:\n        ans = -1\n        seen = {}\n        for x in nums: \n            sm = sum(int(d) for d in str(x))\n            if sm in seen: \n                ans = max(ans, seen[sm] + x)\n                seen[sm] = max(seen[sm], x)\n            else: seen[sm] = x\n        return ans \n```
['Python3']