\begin{tikzpicture}
\node[shape=circle,draw=black] (0) at (0,0) {0};
\node[shape=circle,draw=black] (1) at (2.5,0) {1};
\node[shape=circle,draw=black] (2) at (5,0) {2};
\node[shape=circle,draw=black] (3) at (7.5,0) {3};
\node[shape=circle,draw=black] (4) at (10,0) {4};


\node[below] at (0,-0.4) {a};
\node[below] at (2.5,-0.4) {b};
\node[below] at (5,-0.4) {c};
\node[below] at (7.5,-0.4) {d};
\node[below] at (10,-0.4) {e};

\path [<-](0) edge (1);
\path [<-](1) edge (2);
\path [<-](2) edge (3);
\path [<-](3) edge (4);


\path [->](4) edge[bend right=40] (2); 


\path [->](3) edge[bend right=40] (1); 


\path [->](2) edge[bend right=40] (0);