Add Binary Strings

Add two binary strings and return their sum as a binary string. The input strings represent non-negative integers and contain only the characters '0' and '1'. Handle arbitrarily long strings without using built-in big integer conversion.

Examples
Input: ["11","1"]
Output: "100"
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Add Binary Strings

Add two binary strings and return their sum as a binary string. The input strings represent non-negative integers and contain only the characters '0' and '1'. Handle arbitrarily long strings without using built-in big integer conversion.