current <- positions( i ,  j )
south   <- positions( i , j+1)
east    <- positions(i+1,  j )

documentclass[a4paper]{article}
usepackage[english]{babel}
usepackage[utf8x]{inputenc}
usepackage[T1]{fontenc}
usepackage{amsmath}
usepackage{xcolor} % for textcolor
usepackage{algorithm}
usepackage{algorithmicx}
usepackage{algpseudocode}

% https://www.latex4technics.com/?note=1scm
newlength{maxwidth}
newcommand{algalign}[2]% #1 = text to left, #2 = text to right
{makebox[maxwidth][l]{#1{}}{} #2}

% these make me so sad!
newcommand{iZero}{textcolor{white}{+}textcolor{black}{i}textcolor{white}{0}}
newcommand{jZero}{textcolor{white}{+}textcolor{black}{j}textcolor{white}{0}}
newcommand{iOne}{itextcolor{black}{+1}}
newcommand{jOne}{jtextcolor{black}{+1}}
newcommand{iMinOne}{itextcolor{black}{-1}}
newcommand{jMinOne}{jtextcolor{black}{-1}}

begin{document}

begin{algorithm}
    caption{An algorithm}
    begin{algorithmic}
        settowidth{maxwidth}{current}
        State algalign{current}{$gets$ positions$(iZero, jZero)$}
        State algalign{south}{$gets$ positions$(iZero, jOne)$}
        State algalign{east}{$gets$ positions$(iOne, jZero)$}
    end{algorithmic}
end{algorithm}

end{document}