simple python solution beats 100%
\n    def addNegabinary(self, arr1, arr2):\n        """\n        :type arr1: List[int]\n        :type arr2: List[int]\n        :rtype: List[int]\n        """\n 
```\n    def addNegabinary(self, arr1, arr2):\n        """\n        :type arr1: List[int]\n        :type arr2: List[int]\n        :rtype: List[int]\n        """\n        def num2dec(arr):\n            n = 0\n            for i, num in enumerate(arr[::-1]):\n                n+= ((-2)**i)*num\n            return n\n        num = num2dec(arr1)+num2dec(arr2)\n        \n        \n        if num == 0:\n            digits = [\'0\']\n        else:\n            digits = []\n            while num != 0:\n                num, remainder = divmod(num, -2)\n                if remainder < 0:\n                    num, remainder = num + 1, remainder + 2\n                digits.append(str(remainder))\n        return \'\'.join(digits[::-1])\n```
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