如何处理流程图中的弯曲箭头？

Question

我想要画一张这样的图：

我尝试过并得到：

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{positioning, shapes.geometric}

\begin{document}
\begin{tikzpicture}[node distance=10pt]
  \node[draw, rounded corners, align=center, fill=blue!20, fill opacity=0.6, minimum width=2cm,minimum height=1cm]                        (start)   {\textbf{Firstly}\\$A$};

  \node[draw, below=of start, align=center, fill=blue!40, fill opacity=0.7, minimum width=3cm,minimum height=1cm]                        (step 1)   {\textbf{Secondly}\\$B$};

  \node[draw, below=of step 1, align=center, fill=blue!40, fill opacity=0.7, minimum width=3cm,minimum height=1cm]                        (step 2)   {\textbf{data}\\$A+B$};

   \node[draw, ellipse, right=30pt of step 2, align=center, fill=yellow!40, fill opacity=0.7]                   (step x1)  {e};

    \node[draw, below=of step 2, align=center, fill=blue!40, fill opacity=0.7, minimum width=3cm,minimum height=1cm]                        (step 3)   {\textbf{Finally}};

  \node[draw, ellipse, right=30pt of step 3, align=center, fill=yellow!40, fill opacity=0.7, minimum width=2cm,minimum height=1cm]                   (step x2)  {\textbf{e}};

  \node[draw, rounded corners, fill=blue!40, fill opacity=0.7, below=20pt of step 3]  (end)     {End};

  \draw[->] (start)  -- (step 1);
  \draw[->] (step 1) -- (step 2);
  \draw[->] (step 2) -- (step 3);
  \draw[->] (step 3) -- (end);
  \draw[->] (step 1) -| (step x1);
  \draw[->] (step x1) -- (step 2);
  \draw[->] (step 2) -| (step x2);
  \draw[->] (step x2) -- (step 3);
\end{tikzpicture}
\end{document} 

如何处理分裂和弯曲的箭头？

Answer 1

像这样？

通过使用tikz库arrows.meta、、、、calc和
chains：ext.paths.ortho​positioning​shapes.geometric

\documentclass[margin=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                calc, chains,
                ext.paths.ortho,    % defined in the tikz-ext package
                positioning, 
                shapes.geometric}

\begin{document}
    \begin{tikzpicture}[
node distance = 8mm and 6mm,
  start chain = going below,
   arr/.style = {-Stealth},
     M/.style = {draw, fill=blue!40, minimum height=1cm, text width=1.2cm, align=center},
N/.style args = {#1/#2}{draw, fill=#1, minimum height=1cm, text width=#2, align=center,
                 on chain, join=by arr},
N/.default = blue!40/3cm,
     E/.style = {ellipse, draw, fill=yellow!40, inner xsep= 0pt, minimum width=1cm, align=center}
                        ]
\node[N=blue!20/2cm, rounded corners]   (start) {\textbf{Firstly}\\$A$};
\node[N]    (step 1)    {\textbf{Secondly}\\ $B$};
\node[N]    (step 2)    {\textbf{data}\\ $A+B$};
\node[N]    (step 3)    {\textbf{Finally}};
%
\node[E, right=of $(step 1.east)!0.5!(step 2.east)$]    (step e)  {e};
\node[E, right=of $(step 2.east)!0.5!(step 3.east)$]    (step f)  {f};
%
\node[M, below right=8mm and 0mm of step 3.south west]  (c)     {$C$};
\node[M, below  left=8mm and 0mm of step 3.south east]  (d)     {$D$};
% arrows not considered in join macro
\draw[arr] (step 1.east) to[bend left] (step e);
\draw[arr] (step e) to[bend left] ([yshift=+2mm] step 2.east);
\draw[arr] ([yshift=-2mm] step 2.east) to[bend left] (step f);
\draw[arr] (step f) to[bend left] (step 3.east);
%
\draw[arr]  (step 3) |-| (c);                    % <---
\draw[arr]  (step 3) |-| (d);                    % <---
    \end{tikzpicture}
\end{document}