[To Review] 문제 잘못 이해했지만, sort하는 기법

Daily Practices/April/Week 4th/3038 - LeetCode.py

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+# https://leetcode.com/problems/maximum-number-of-operations-with-the-same-score-i/description/
+
+from typing import List
+from collections import Counter
+
+class Solution:
+    def maxOperations(self, nums: List[int]) -> int:
+        numsCounter, possibleSums = Counter(nums), self.getPossibleSums(nums)
+
+        result = 0
+        for possibleSum in possibleSums:
+            numsOperations = self.getNumsOperations(possibleSum, numsCounter)
+            result = max(result, numsOperations)
+
+        return result
+
+    def getPossibleSums(self, nums):
+        possible_sums = set()
+        for i in range(len(nums)):
+            for j in range(i + 1, len(nums)):
+                possible_sums.add(nums[i] + nums[j])
+        return possible_sums
+
+    def getNumsOperations(self, possibleSum, numsCounter):
+        numsCounter = numsCounter.copy()
+        sortedNums = sorted(numsCounter.keys(), reverse=True)
+        left, right = 0, len(sortedNums) - 1
+
+        result = 0
+        while left <= right:
+            currentSum = sortedNums[left] + sortedNums[right]
+            if currentSum < possibleSum:
+                right -= 1
+            elif currentSum > possibleSum:
+                left += 1
+            else:
+                if left == right:
+                    if numsCounter[sortedNums[left]] >= 2:
+                        numsCounter[sortedNums[left]] -= 2
+                        result += 1
+
+                    if numsCounter[sortedNums[left]] <= 2:
+                        break
+                else:
+                    if numsCounter[sortedNums[left]] > 0 and numsCounter[sortedNums[right]] > 0:
+                        numsCounter[sortedNums[left]] -= 1
+                        numsCounter[sortedNums[right]] -= 1
+                        result += 1
+                if numsCounter[sortedNums[left]] == 0:
+                    left += 1
+                if numsCounter[sortedNums[right]] == 0:
+                    right -= 1
+
+        return result
+
+if __name__ == "__main__":
+    sample = Solution()
+    print(sample.maxOperations([3,2,6,1,4]))