File:Structured program patterns.svg

% lualatex file.tex
% inkscape --export-plain-svg --export-filename=file.svg file.pdf
\documentclass[border=0.5cm]{standalone}

\usepackage{fontspec}
\setmainfont{Liberation Sans}
\usepackage[svgnames]{xcolor}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usetikzlibrary{calc}
\usetikzlibrary{arrows.meta}
\usetikzlibrary{shapes.geometric}

\tikzset{every picture/.style={
    semithick,
    baseline=(current bounding box.center)
}

\def\st{statement}

\begin{document}
\begin{tikzpicture}[
        MediumBlue,
        every node/.style={draw, rectangle, inner sep=6pt, outer sep=0},
    ]
    \node (M) {\st};
    \node[above=0 of M] {\st};
    \node[below=0 of M] {\st};

\end{tikzpicture}%
\hspace{0.5cm}%
\begin{tikzpicture}[
        DarkGreen,
        every node/.style={draw, rectangle, inner sep=6pt},
    ]
    \node (M) at (0,0) {\st};
    \node[above=0.2cm of M] (T) {\st};
    \node[below=0.2cm of M] (B) {\st};

    \draw[-Latex] (T.north) + (0, 0.5) -> (T.north);
    \draw (T.south) -> (M.north);
    \draw (M.south) -> (B.north);
    \draw[-Latex] (B.south) -> +(0, -0.5);
\end{tikzpicture}%
\hspace{2cm}%
\begin{tikzpicture}[MediumBlue]
    \coordinate (TRC) at (4, 0.75);
    \draw (0,0) rectangle (4, 0.75);
    \draw (0,-2.25) rectangle (2,0);
    \draw (2,-2.25) rectangle (4,0);
    \draw (0,0.75) -- (2,0);
    \draw (4,0.75) -- (2,0);

    \node at (2, 0.5) {condition};
    \node at (1, -1.125) {\st};
    \node at (3, -1.125) {\st};
    \node[anchor=south west, minimum height=0.5cm] at (0,0) {y};
    \node[anchor=south east, minimum height=0.5cm] at (4,0) {n};
\end{tikzpicture}%
\hspace{0.5cm}%
\begin{tikzpicture}[DarkGreen]
    \node[draw, diamond, aspect=2, inner sep=1pt, outer sep=0] (C) {condition};
    \node[draw, rectangle, below left=0.5 of C, inner sep=6pt] (Y) {\st};
    \node[draw, rectangle, below right=0.5 of C, inner sep=6pt] (N) {\st};
    \coordinate (F) at ($(C.south) + (0,-1.5)$);

    \draw[-Latex] (C.north) + (0, 0.5) -> (C.north);
    \draw (C) -| node[below right] {y} (Y);
    \draw (C) -| node[below left] {n} (N);
    \draw[-Latex] (Y.south) -> +(0, -0.5);
    \draw[-Latex] (N.south) -> +(0, -0.5);
    \draw[-Latex, dashed] (Y.south) + (0, -0.5) |- (F);
    \draw[-Latex, dashed] (N.south) + (0, -0.5) |- (F);
    \draw[-Latex, dashed] (F.south) -> +(0,-0.5);
\end{tikzpicture}%
\hspace{2cm}%
\begin{tikzpicture}[MediumBlue]
    \draw (0,0) rectangle (3.25, 2.25);
    \draw (0,0) rectangle (4, 3);

    \node at (2, 2.635) {condition};
    \node at (1.625, 1.125) {\st};
\end{tikzpicture}%
\hspace{0.5cm}%
\begin{tikzpicture}[DarkGreen]
    \node[draw, diamond, aspect=2, inner sep=1pt, outer sep=0] (C) {condition};
    \node[draw, rectangle, below=0.5 of C, inner sep=6pt] (Y) {\st};
    \coordinate (F) at ($(C.south) + (0,-1.5)$);

    \draw[-Latex] (C.north) + (0, 0.5) -> (C.north);
    \draw (C) -- node[right] {y} (Y);
    \draw[-Latex] (C.west) -- node[below] {n} ++(-0.5, 0) |- (F)
    -- +(0, -0.5);
    \draw[-Latex] (Y.south) |- +(1.5, -0.15) |- ($(C.north) + (0, 0.35)$);
\end{tikzpicture}%
\end{document}