:algorithm: \begin{algorithm} \caption{Quicksort} \begin{algorithmic} \PROCEDURE{Quicksort}{$A, p, r$} \IF{$p < r$} \STATE $q = $ \CALL{Partition}{$A, p, r$} \STATE \CALL{Quicksort}{$A, p, q - 1$} \STATE \CALL{Quicksort}{$A, q + 1, r$} \ENDIF \ENDPROCEDURE \PROCEDURE{Partition}{$A, p, r$} \STATE $x = A[r]$ \STATE $i = p - 1$ \FOR{$j = p$ \TO $r - 1$} \IF{$A[j] < x$} \STATE $i = i + 1$ \STATE exchange $A[i]$ with $A[j]$ \ENDIF \STATE exchange $A[i]$ with $A[r]$ \ENDFOR \ENDPROCEDURE \end{algorithmic} \end{algorithm} ::

\begin{algorithm}
  \caption{Quicksort}
  \begin{algorithmic}
  \PROCEDURE{Quicksort}{$A, p, r$}
      \IF{$p < r$}
          \STATE $q = $ \CALL{Partition}{$A, p, r$}
          \STATE \CALL{Quicksort}{$A, p, q - 1$}
          \STATE \CALL{Quicksort}{$A, q + 1, r$}
      \ENDIF
  \ENDPROCEDURE
  \PROCEDURE{Partition}{$A, p, r$}
      \STATE $x = A[r]$
      \STATE $i = p - 1$
      \FOR{$j = p$ \TO $r - 1$}
          \IF{$A[j] < x$}
              \STATE $i = i + 1$
              \STATE exchange
              $A[i]$ with $A[j]$
          \ENDIF
          \STATE exchange $A[i]$ with $A[r]$
      \ENDFOR
  \ENDPROCEDURE
  \end{algorithmic}
  \end{algorithm}