Create max-sum-of-a-pair-with-equal-sum-of-digits.py

Python/max-sum-of-a-pair-with-equal-sum-of-digits.py

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+# Time:  O(nlogr), r is max(nums)
+# Space: O(n)
+
+# greedy
+class Solution(object):
+    def maximumSum(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        def sum_digits(x):
+            result = 0
+            while x:
+                result += x%10
+                x //= 10
+            return result
+
+        lookup = {}
+        result = -1
+        for x in nums:
+            k = sum_digits(x)
+            if k not in lookup:
+                lookup[k] = x
+                continue
+            result = max(result, lookup[k]+x)
+            if x > lookup[k]:
+                lookup[k] = x
+        return result