\section{Introdu\c{c}\~ao}
\label{sec:introduction}
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\begin{figure*}
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\centering
  \includegraphics{figs/minimalperfecthash-ph-mph.ps}
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\caption{(a) Perfect hash function\quad  (b) Minimal perfect hash function}
\label{fig:minimalperfecthash-ph-mph}
\end{figure*}