Ytukyg

I'm looking for a way to create a command with which Latex can automatically generate a table with a given amount of columns, and automatically fills in the column numbers as headers.

I'm looking for something like this:

newcommand{CountBox}[1]{

    begin{flushright}

        begin{tabular}{*{#1}{|l}}

        hline

        multicolumn{1}{|c|}{1} #1  \ hline

                                #1   \ hline

        end{tabular}   

    end{flushright}

}

Where the following command creates the following table:

CountBox{6}

And the following command creates the following table:

CountBox{3}

I seem to get stuck on having to manually input the ampersands into the multicolumn command (have tried loop, while, and expandafter)

Thanks for the help!

Just in case the original code for the 6 column table:

begin{flushright}

    begin{tabular}{*{7}{|l}}

    hline

    multicolumn{1}{|c|}{1} & 2 & 3 & 4 & 5 & 6 \ hline 

                            &   &   &   &   &   \ hline



    end{tabular}   

end{flushright}

With foreach in TikZ:

documentclass{article}       

usepackage{tikz}

usepackage{etoolbox}

usetikzlibrary{

    positioning,

    shapes.multipart

    }

tikzset{

    mynode/.style={

        draw,

        rectangle split,

        rectangle split parts=2,

        text centered,

    },

}

newcommand{CountBox}[1]{%

    begin{tikzpicture}

        node[mynode] (1) {1};

        ifnumcomp{#1}{=}{1}{}{%

            foreach mynum 

                [evaluate=mynum as myprev using int(mynum-1)]  

                in {2,...,#1}

            node[mynode,xshift=-pgflinewidth,anchor=west] (mynum) at (myprev.east) {mynum};

            }%

    end{tikzpicture}%

    }



begin{document}

CountBox{1} 



CountBox{3}



CountBox{6}



CountBox{2} 

CountBox{4}

CountBox{7} 

end{document}

Here is an expl3 implementation. With the help of array and its w column specifier, all columns can be made as wide as the last (with the largest number).

documentclass{article}



usepackage{xparse,array}



ExplSyntaxOn

NewDocumentCommand{CountBox}{m}

 {

  % measure the wider number

  hbox_set:Nn l_tmpa_box { #1 }

  dim_set:Nn l_tmpa_dim { box_wd:N l_tmpa_box }

  % do as many columns as specified

  begin{tabular}{|*{#1}{w{c}{l_tmpa_dim}|}}

  hline

  % do '<number> &' one less than specified, then add the last number

  int_step_function:nN { #1 - 1 } __phlemp_countbox_head:n #1 \

  hline

  % generate as many &'s as necessary to fill the second row

  prg_replicate:nn { #1 - 1 } { & } \

  hline

  end{tabular}

 }



% auxiliary function for adding the & after the number

cs_new_protected:Nn __phlemp_countbox_head:n { #1 & }

ExplSyntaxOff



begin{document}



CountBox{3} CountBox{10}



end{document}

The following uses multido to generate the column numbering sequence and blank row. A similar approach to egreg's uses array's w{<align>}{<width>} to set the column width to the widest element:

documentclass{article}



usepackage{multido,array}



newcounter{boxCount}

newlength{boxCountwd}



makeatletter

newcommand{CountBox}[1]{%

  setcounter{boxCount}{0}% Reset boxCount

  settowidth{boxCountwd}{#1}% Measure widest element

  defCountBoxSeq{@gobble}%

  defCountBoxSeqPhantom{@gobble}%

  multido{i=1+1}{#1}{%

    xdefCountBoxSeq{CountBoxSeq & i}%

    xdefCountBoxSeqPhantom{CountBoxSeqPhantom &}%

  }%

  noindent

  begin{tabular}{ *{#1}{|w{c}{boxCountwd}} | }

    hline

    CountBoxSeq \

    hline

    CountBoxSeqPhantom \

    hline

  end{tabular}%

}

makeatother



begin{document}



CountBox{5}



end{document}