Levenshtein Distance

function levenshteinDistance(
    string memory a,
    string memory b
) public pure returns (uint256) {
    bytes memory bytesA = bytes(a);
    bytes memory bytesB = bytes(b);
    
    uint256 lenA = bytesA.length;
    uint256 lenB = bytesB.length;
    
    // Handle empty string cases
    if (lenA == 0) return lenB;
    if (lenB == 0) return lenA;
    
    // Create distance matrix (two-row optimization)
    uint256[] memory prevRow = new uint256[](lenB + 1);
    uint256[] memory currRow = new uint256[](lenB + 1);
    
    // Initialize first row
    for (uint256 j = 0; j <= lenB; j++) {
        prevRow[j] = j;
    }
    
    // Fill in the matrix
    for (uint256 i = 1; i <= lenA; i++) {
        currRow[0] = i;
        
        for (uint256 j = 1; j <= lenB; j++) {
            uint256 cost = (bytesA[i - 1] == bytesB[j - 1]) ? 0 : 1;
            
            // Minimum of: deletion, insertion, substitution
            uint256 deletion = prevRow[j] + 1;
            uint256 insertion = currRow[j - 1] + 1;
            uint256 substitution = prevRow[j - 1] + cost;
            
            currRow[j] = _min3(deletion, insertion, substitution);
        }
        
        // Swap rows for next iteration
        (prevRow, currRow) = (currRow, prevRow);
    }
    
    return prevRow[lenB];
}