Cfrgtkky

I am using ACM format for writing a paper. I use the following algorithm sample that is taken from this form. I want to add input and output before MyProcedure. I tried many ways but all fails. Can someone guide me? Thank you

usepackage{algorithm}

usepackage[noend]{algpseudocode}

    begin{algorithm}

    caption{My algorithm}label{euclid}

    begin{algorithmic}[1]

     % Input:

     % Output: 

    Procedure{MyProcedure}{}

    State $textit{stringlen} gets text{length of }textit{string}$

    State $i gets textit{patlen}$

    BState emph{top}:

    If {$i > textit{stringlen}$} Return false

    EndIf

    State $j gets textit{patlen}$

    BState emph{loop}:

    If {$textit{string}(i) = textit{path}(j)$}

    State $j gets j-1$.

    State $i gets i-1$.

    State textbf{goto} emph{loop}.

    State textbf{close};

    EndIf

    State $i gets i+max(textit{delta}_1(textit{string}(i)),textit{delta}_2(j))$.

    State textbf{goto} emph{top}.

    EndProcedure

    end{algorithmic}

    end{algorithm}

Answer:

To add input and output before MyProcedure a possibility is to add the text before begin{algorithmic} with starred hspace hspace*{}(see 6.3.3 Horizontal Space) and the indentation algorithmicindent (see 4.1 Blocks and loops). LaTeX normally removes horizontal space at the beginning of a line, to preserve this space, use the starred version.

 ...

 hspace*{algorithmicindent} textbf{Input} \

 hspace*{algorithmicindent} textbf{Output} 

 begin{algorithmic}[1]

 ...

Complete full MWE:
A minimal working example (MWE) starts with documentclass and ends with end{document}.

To complete the MWE and to avoid the following error:

! Undefined control sequence. BState ->State algbackskip l.24
BState

You have to use the following definition (the solution is from @Werner see: Undefined control sequence.BState ->State algbackskip BState):

makeatletter

% Reinsert missing algbackskip

defalgbackskip{hskip-ALG@thistlm}

makeatother

MWE:

documentclass{article}

usepackage{algorithm}

usepackage[noend]{algpseudocode}



makeatletter

% Reinsert missing algbackskip

defalgbackskip{hskip-ALG@thistlm}

makeatother



begin{document}

    begin{algorithm}

    caption{My algorithm}label{euclid}

    hspace*{algorithmicindent} textbf{Input} \

    hspace*{algorithmicindent} textbf{Output} 

    begin{algorithmic}[1]

    Procedure{MyProcedure}{}

%    Procedure{MyProcedure}{$x,y$}

%     % Input:

%     Comment{Input: x}

%     % Output:

%     Comment{Output:y}

    State $textit{stringlen} gets textit{length of } textit{string}$

    State $i gets textit{patlen}$

    BState emph{top}:

    If {$i > textit{stringlen}$} Return false

    EndIf

    State $j gets textit{patlen}$

    BState emph{loop}:

    If {$textit{string}(i) = textit{path}(j)$}

    State $j gets j-1$.

    State $i gets i-1$.

    State textbf{goto} emph{loop}.

    State textbf{close};

    EndIf

    State $i gets i+max(textit{delta}_1(textit{string}(i)),textit{delta}_2(j))$.

    State textbf{goto} emph{top}.

    EndProcedure

    end{algorithmic}

    end{algorithm}

end{document} 

Alternative: You can add the input and output after MyProcedure with Procedure{MyProcedure}{$x,y$} ...

or Comment{Input: x}/Comment{Output: y}.

If one is using the algorithmic environment, one can make REQUIRE and ENSURE to print Input and Output by adding in the preamble:

renewcommand{algorithmicrequire}{textbf{Input:}}

renewcommand{algorithmicensure}{textbf{Output:}}