1
class Solution:
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    def largestVariance(self, s: str) -> int:
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        def maxSubArray(nums: List[int]):
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            ans = -float("inf")
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            runningSum = 0
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            seen = False
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            for x in nums:
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                if x < 0:
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                    seen = True
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                runningSum += x
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                if seen:
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                    ans = max(ans, runningSum)
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                else:
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                    ans = max(ans, runningSum - 1)
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                if runningSum < 0:
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                    runningSum = 0
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                    seen = False
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            return ans
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        f = set()
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        a = ""
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        for x in s:
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            if x not in f:
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                a += x
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                f.add(x)
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        n = len(s)
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        res = 0
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        for j in range(len(a) - 1):
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            for k in range(j + 1, len(a)):
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                x = a[j]
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                y = a[k]
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                arr = []
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                for i in range(n):
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                    if s[i] != x and s[i] != y:
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                        continue
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                    elif s[i] == x:
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                        arr.append(1)
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                    else:
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                        arr.append(-1)
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                res = max(res, maxSubArray(arr), maxSubArray([-x for x in arr]))
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        return res