Solidity code to find space, octothorp, or ampersand and remove them

remove.sol

  function remove(string calldata input) external pure returns(bytes memory result, uint256 resultLength){
    //bit mask
    bytes1 precheck = bytes1(" ");

    uint256 needlesLength = 3;
    bytes1[] memory needles = new bytes1[](needlesLength);
    needles[0] = bytes1(" "); // 0010 0000, 32, 20
    needles[1] = bytes1("#"); // 0010 0111, 35, 23
    needles[2] = bytes1("&"); // 0010 1011, 38, 26    

    bytes1 char;
    bool add = true;
    bytes memory inputBytes = bytes(input);
    uint256 inputLength = inputBytes.length;
    result = new bytes(inputBytes.length);

    unchecked{
      for(uint256 i = 0; i < inputLength; ++i){
        char = inputBytes[i];
        if(uint8(char & precheck) > 0){
          for(uint256 j = 0; j < needlesLength; ++j ){
            if(char == needles[j]){
              add = false;
              break;
            }
          }
        }

        if(add)
          result[resultLength++] = char;
        else
          add = true;
      }
    }

    return (result, resultLength);
  }