# how can draw this picture

itlo 07/11/2018. 2 answers, 990 views

I tried to do that but :(

\begin{center}
\begin{figure}[!h]
\begin{tikzpicture}[>=stealth,line width=0.8pt]
%les sommets
\draw (0,0)node (0)[]{$\bf 0$};
\draw (2,0)node (1)[]{$\bf 1$};
\draw (4,0)node (2)[]{$\bf 2$};
\draw (6,0)node (x)[]{$\bf x$};
\draw (8,0)node (n-1)[]{$\bf n-1$};
\draw (10,0)node (n)[]{$\bf n$};
\draw (11,0)node (n+1)[]{$\bf n+1$};
%les fleches
\draw [->] (n)to [bend right] (n-1);
\draw [->] (n)to [bend right] (x);
\draw [->] (n)to [bend right] (1);
\draw [->] (n)to [bend right] (2);
\draw [->] (n)to [bend right] (0);
\draw [->] (4)to [bend right] (n+1);
%\draw (-3.5,3.7) node [scale=0.7] {$\alpha_{1}$};
%\draw (-2.5,3.7) node [scale=0.7] {$\alpha_{n-2}$};
%\draw (-1.5,3.7) node [scale=0.7] {$\alpha_{n-1}$};
%\draw (-0.5,3.7) node [scale=0.7] {$\alpha_{n}$};
\end{tikzpicture}
\end{figure}
\end{center}

Torbjørn T. 07/11/2018.

Here is a slightly different approach, using a \foreach loop to place the nodes, and the quotes library to add the edge nodes. \bf has been deprecated for about 25 years, so I used \mathbf{..} instead.

\documentclass[border=5mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{quotes}
\begin{document}

\begin{tikzpicture}[
>=stealth,line width=0.8pt,
every edge quotes/.style={font=\footnotesize,pos=0.7,above}
]
%les sommets
\foreach [count=\i] \txt in {0,1,2,\dots,n-1,n,n+1}
\node (n-\i) at (\i*2,0) {$\mathbf{\txt}$};

\draw [->] (n-6) to[bend right,"$\alpha_n$"] (n-1);
\draw [->] (n-6) to[bend right,"$\alpha_{n-1}$"] (n-2);
\draw [->] (n-6) to[bend right,"$\alpha_{n-2}$"] (n-3);
\draw [->] (n-6) to[bend right,"$\alpha_n$"above left] (n-5);

\draw [->] (n-6) to[bend right,"$\lambda$"{midway,below}] (n-7);

\end{tikzpicture}
\end{document}

Max 07/11/2018.

Apart from a complete MWE, you already did most of the work! I only added nodes in the \draw ... to commands.

Additionally, you shouldn't use \bf, instead use \bfseries. And I've added some scopes to make changing options for all nodes in that scope easier.

\documentclass[tikz]{standalone}

\begin{document}
\begin{tikzpicture}[>=stealth,line width=0.8pt]
%les sommets
\begin{scope}[every node/.style={font=\bfseries}]
\draw (0,0)  node (0)   {$0$};
\draw (2,0)  node (1)   {$1$};
\draw (4,0)  node (2)   {$2$};
\draw (6,0)  node (x)   {$x$};
\draw (8,0)  node (n-1) {$n-1$};
\draw (10,0) node (n)   {$n$};
\draw (12,0) node (n+1) {$n+1$};
\end{scope}
%les fleches
\begin{scope}[every node/.style={font=\small,midway,below}]
\draw [->] (n)to [bend right] node{$a_{1}$} (n-1);
\draw [->] (n)to [bend right] node{$a_{n-x}$} (x);
\draw [->] (n)to [bend right] node{$a_{n-2}$} (1);
\draw [->] (n)to [bend right] node{$a_{n-1}$} (2);
\draw [->] (n)to [bend right] node{$a_n$} (0);
\draw [->] (n)to [bend right] node{$\lambda$} (n+1);
\end{scope}
\end{tikzpicture}
\end{document}