foreach loop for adding arcs using commands path and edge

Question

i want to know how to use the foreach loop for adding arcs using commands \path and edge. For instance, the following code generates a cycle and the task is to add the arcs not manually:

\documentclass[border=2pt,tikz]{standalone}
\usepackage{wasysym}
\usetikzlibrary{decorations.pathreplacing,automata,arrows,shadows,patterns,shapes}
\begin{document}

\newlength{\rnodo}
\newlength{\radio}
\setlength{\rnodo}{10pt}
\setlength{\radio}{3.00cm}
\tikzstyle{nondirected}=[thick]
\tikzstyle{labels}=[inner sep=0pt,font=\scriptsize,auto,circle]
\tikzstyle{main node}=[outer sep=1,inner sep=0,ellipse,thick,draw,minimum size=2\rnodo,fill=black!10]

\newcommand\n{10}
\begin{tikzpicture}   
\foreach \x in {1,...,\n}{
    \coordinate (cn\x) at ({(1+2*\x)*180/\n-90}:\radio);
    \node (n\x) at (cn\x) {$n_{\x}$};
}

\path[nondirected]
(n1) edge node[labels] {$\oplus$}  (n2)
(n2) edge node[labels] {$\oplus$}  (n3)
(n3) edge node[labels] {$\ominus$}  (n4)
(n4) edge node[labels] {$\ocircle$}  (n5)
(n5) edge node[labels] {$\ocircle$}  (n6)
(n6) edge node[labels] {$\oplus$}  (n7)
(n7) edge node[labels] {$\oplus$}  (n8)
(n8) edge node[labels] {$\ominus$}  (n9)
(n9) edge node[labels] {$\ominus$}  (n10)
(n10) edge node[labels] {$\ocircle$}  (n1);
\end{tikzpicture}

\end{document}

In this LINK, I've been given some alternatives using command \draw. I've tried to adapt it, but with no luck so far.

Answer 1

All can be done with two simple loops: one to place the nodes and the other one to place the links and labels:

\def\n{10}
\begin{tikzpicture}
\foreach \x in {0,...,\the\numexpr\n-1\relax}
    \node (n\x) at ({(1+2*(\x+1))*180/\n-90}:\radio) {$n_{\the\numexpr\x+1\relax}$};
\foreach \Texto [count=\x]  in {\oplus,\oplus,\oplus,\ominus,\ocircle,\ocircle,\oplus,\oplus,\ominus,\ominus}
{
  \pgfmathsetmacro{\ttt}{int(mod(\numexpr\x+\n-1\relax,\n))}
  \pgfmathsetmacro{\mmm}{int(mod(\numexpr\x+\n-2\relax,\n))}
  \draw[nondirected] (n\mmm) -- node[labels] {$\Texto$} (n\ttt);
}
\end{tikzpicture}

The complete code:

\documentclass{article}
\usepackage{tikz}
\usepackage{wasysym}
\usetikzlibrary{decorations.pathreplacing,automata,arrows,shadows,patterns,shapes}

\newlength\rnodo
\newlength\radio
\setlength{\rnodo}{10pt}
\setlength{\radio}{3.00cm}

\tikzset{
  nondirected/.style={thick},
  labels/.style={
    inner sep=0pt,
    font=\scriptsize,
    auto,
    circle},
  main node/.style={
    outer sep=1,
    inner sep=0,
    ellipse,
    thick,
    draw,
    minimum size=2\rnodo,
    fill=black!10}
}

\begin{document}

\def\n{10}
\begin{tikzpicture}
\foreach \x in {0,...,\the\numexpr\n-1\relax}
    \node (n\x) at ({(1+2*(\x+1))*180/\n-90}:\radio) {$n_{\the\numexpr\x+1\relax}$};
\foreach \Texto [count=\x]  in {\oplus,\oplus,\oplus,\ominus,\ocircle,\ocircle,\oplus,\oplus,\ominus,\ominus}
{
  \pgfmathsetmacro{\ttt}{int(mod(\numexpr\x+\n-1\relax,\n))}
  \pgfmathsetmacro{\mmm}{int(mod(\numexpr\x+\n-2\relax,\n))}
  \draw[nondirected] (n\mmm) -- node[labels] {$\Texto$} (n\ttt);
}
\end{tikzpicture}

\end{document}

Explanation

The first loop

\foreach \x in {0,...,\the\numexpr\n-1\relax}
    \node (n\x) at ({(1+2*(\x+1))*180/\n-90}:\radio) {$n_{\the\numexpr\x+1\relax}$};

is clear; it's almost the original, but I looped from 0 to n-1 instead of from 1 to n because in the second loop some modular arithmetic will be used.

The second loop (forgetting the labels in this explanation, which are not important here) could be simplified to

\foreach \x in {1,...,\n}
{
  \draw[nondirected] (n int(mod(\x+\n-2,\n))) -- (n int(mod(\x+\n-1,\n)));
}

so it joins n(n-1) to n0, n0 to n1,...,n(n-2) to n(n-1). So, simply changing \n to 20 and providing the labels for the additional elements, as in

\def\n{20}
...
\foreach \Texto [count=\x]  in {\oplus,\oplus,\oplus,\ominus,\ocircle,\ocircle,\oplus,\oplus,\ominus,\ominus,\oplus,\oplus,\oplus,\ominus,\ocircle,\ocircle,\oplus,\oplus,\ominus,\ominus}
{...}

you get

Answer 2

Somewhat crude, but serviceable...

\documentclass[tikz,border=5]{standalone}
\usepackage{wasysym}
\usetikzlibrary{shapes.geometric}
\begin{document}
\tikz\node [regular polygon, regular polygon sides=10, 
  draw, minimum size=5cm, rotate=-108] (p) {} 
  \foreach \l [count=\i] in {\oplus,\oplus,\ominus,\ocircle,\ocircle,
      \oplus,\oplus,\ominus,\ominus,\oplus}{ 
    node [circle, inner sep=0, fill=white] at (p.corner \i) {\strut$n_{\i}$}
    node [circle, font=\scriptsize, anchor=\i*36+54-108, inner sep=0] 
      at (p.side \i) {$\l$} };
\end{document}

Answer 3

I'm having a bit of trouble with the labels because I wanted to use an array list, but it refuses to work although the code is fine. However it's getting late here, so I'll take a look at it tomorrow. For now, here's the foreach for the lines.

Output

Code

\documentclass{article}
\usepackage{tikz}
\usepackage{wasysym}
\usetikzlibrary{decorations.pathreplacing,automata,arrows,shadows,patterns,shapes}

\newcommand{\rnodo}{10}
\newcommand{\radio}{3.00cm}
\tikzstyle{nondirected}=[thick]
\tikzstyle{labels}=[inner sep=0pt,font=\scriptsize,auto,circle]
\tikzstyle{main node}=[outer sep=1,inner sep=0,ellipse,thick,draw,minimum size=2pt*\rnodo,fill=black!10]



\begin{document}
\def\n{10}
%\newcommand\mylist{{"$\oplus$","$\oplus$","$\ominus$","$\ocircles$","$\ocircles$","$\oplus$","$\oplus$","$\ominus$","$\ominus$"}}

\begin{tikzpicture}   
\foreach \x in {1,...,\n}{
    \coordinate (cn\x) at ({(1+2*\x)*180/\n-90}:\radio);
    \node (n\x) at (cn\x) {$n_{\x}$};
}

\foreach \lab [count=\xi, remember=\xi as \lastx (initially 1)] in {1,...,11}{
\ifnum\xi<11
\path[nondirected] (n\lastx) edge node[labels] {} (n\xi);
\else
\path[nondirected] (n10) edge node[labels] {$\ocircle$} (n1);
\fi
}
\end{tikzpicture}
\end{document}