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class Solution:
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    def xorQueries(self, arr: List[int], queries: List[List[int]]) -> List[int]:
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        """
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        arr = [1,3,4,8], queries = [[0,1],[1,2],[0,3],[3,3]]
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        find pref xor of arr
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        pref = [x,x,x,x]
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        for each query find the left and right indices
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        the xor for range (l, r) would be pref[r] xor pref[l-1]
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        """
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        n, m = len(queries), len(arr)
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        answer = [1] * n
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        pref = [1] * m
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        pref[0] = arr[0]
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        if m > 1:
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            for i in range(1, m):
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                pref[i] = pref[i - 1] ^ arr[i]
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        for i, (l, r) in enumerate(queries):
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            if l == 0:
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                answer[i] = pref[r]
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            else:
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                answer[i] = pref[r] ^ pref[l - 1]
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        return answer