\documentclass[tikz,border=5pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing,calligraphy}
\usetikzlibrary{calc}
\usetikzlibrary{shapes.geometric}
\usetikzlibrary{arrows.meta}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{textcomp,amssymb,amsmath,amsthm}
\usepackage{xcolor}
\tikzset{sttriangle/.style={
draw=black,
fill=white,
regular polygon,
regular polygon sides=3,
minimum size = 0pt,
inner sep=1pt
}}
\tikzset{stcircle/.style={
fill=white,
draw=black,
circle,inner sep=1pt,
minimum size = 1.5em
}}
\tikzset{rednode/.style={
fill=white,
draw=black,
circle,
inner sep=1pt,
minimum size = 1.5em
}}
\tikzset{blacknode/.style={
text=white,
fill=black,
draw=black,
circle,
inner sep=1pt,
minimum size = 0.5em
}}
\tikzset{splitter/.style={
fill=black,
circle,
inner sep=0pt,
minimum size = 4pt
}}
\tikzset{term/.style={
draw=black,
fill=black,
rectangle,
inner sep=0pt,
minimum size=4pt
}}
\tikzset{chooser/.style={
draw=black,
fill=white,
circle,
inner sep=0pt,
minimum size = 4pt
}}
\tikzset{saturated/.style={very thick}}
\tikzset{fluid/.style={}}
\tikzset{OutPrio/.tip = {||.}}
\begin{document}
\begin{tikzpicture}[x=1cm,y=1cm,>=latex]
\begin{scope}[xshift=0cm]
\node[splitter] (s0) at (0,0) {};
\node[splitter] (s1) at (1,0) {};
\node[term] (i0) at (-1,1) {}; \draw (-1,1) node[anchor=east] {$1$};
\node[term] (i1) at (-1,-1) {}; \draw (-1,-1) node[anchor=east] {$0$};
\node[term] (o0) at (2,1) {}; \draw (2,1) node[anchor=west] {$1$};
\node[term] (o1) at (2,-1) {}; \draw (2,-1) node[anchor=west] {$0$};
\draw[->,fluid] (i0) -- (s0) node[midway,above=-3pt,sloped] {$1$};
\draw[->,fluid] (i1) -- (s0) node[midway,above=-3pt,sloped] {$0$};
\draw[->,fluid] (s0) -- (s1) node[midway,above=-3pt,sloped] {$1$};
\draw[->,fluid] (s1) -- (o0) node[midway,above=-3pt,sloped] {$1$};
\draw[->,fluid] (s1) -- (o1) node[midway,above=-3pt,sloped] {$0$};
\end{scope}
\begin{scope}[xshift=4.5cm]
\node[splitter] (s0) at (0,0) {};
\node[splitter] (s1) at (1,0) {};
\node[term] (i0) at (-1,1) {}; \draw (-1,1) node[anchor=east] {$1$};
\node[term] (i1) at (-1,-1) {}; \draw (-1,-1) node[anchor=east] {$1$};
\node[term] (o0) at (2,1) {}; \draw (2,1) node[anchor=west] {$1$};
\node[term] (o1) at (2,-1) {}; \draw (2,-1) node[anchor=west] {$0$};
\draw[->,saturated] (i0) -- (s0) node[midway,above=-3pt,sloped] {$1/2$};
\draw[->,saturated] (i1) -- (s0) node[midway,above=-3pt,sloped] {$1/2$};
\draw[->,fluid] (s0) -- (s1) node[midway,above=-3pt,sloped] {$1$};
\draw[->,fluid] (s1) -- (o0) node[midway,above=-3pt,sloped] {$1$};
\draw[->,fluid] (s1) -- (o1) node[midway,above=-3pt,sloped] {$0$};
\end{scope}
\begin{scope}[xshift=9cm]
\node[splitter] (s0) at (0,0) {};
\node[splitter] (s1) at (1,0) {};
\node[term] (i0) at (-1,1) {}; \draw (-1,1) node[anchor=east] {$1$};
\node[term] (i1) at (-1,-1) {}; \draw (-1,-1) node[anchor=east] {$1$};
\node[term] (o0) at (2,1) {}; \draw (2,1) node[anchor=west] {$1$};
\node[term] (o1) at (2,-1) {}; \draw (2,-1) node[anchor=west] {$1$};
\draw[->,saturated] (i0) -- (s0) node[midway,above=-3pt,sloped] {$\frac{1}{2}$};
\draw[->,saturated] (i1) -- (s0) node[midway,above=-3pt,sloped] {$\frac{1}{2}$};
\draw[->,fluid] (s0) -- (s1) node[midway,above=-3pt,sloped] {$1$};
\draw[->,fluid] (s1) -- (o0) node[midway,above=-3pt,sloped] {$\frac{1}{2}$};
\draw[->,fluid] (s1) -- (o1) node[midway,above=-3pt,sloped] {$\frac{1}{2}$};
\end{scope}
\end{tikzpicture}
\end{document}