[Tex/LaTex] Draw a box around selected entries of array

arraysboxesdraw

enter image description here
I want to draw a dashed-line box as show in picture.
Can someone help? Here is the latex code I used for that array:

\begin{array}{ccccccccccccccc}
c^{(1)} & \geq & c^{(2)} & \geq & \cdots & \geq & c^{(j)} & \geq & \cdots & \geq & c^{((N-1)K+1)} & \geq & \cdots & \geq & c^{(NK)}\\
\downarrow &  & \downarrow &  &  &  & \downarrow &  &  &  & \downarrow & & & & \downarrow \\
\gamma^{(1)} &  & \gamma^{(2)} &  & \cdots &  & \gamma^{(j)} &  & \cdots &  & \gamma^{((N-1)K+1)}& &\cdots &  & \gamma^{(NK)}
\end{array}

Best Answer

With a simple array environment:

\documentclass[12pt]{article}
\usepackage{array,amsmath}
\begin{document}

$\arraycolsep=2pt
\begin{array}{ | *7c | *8c }\cline{1-7}
  \rule{0pt}{3ex}% more  vertical space for 1st line
  c^{(1)} & \geq & c^{(2)} & \geq & \cdots & \geq & c^{(j)} & \geq & \cdots & \geq & 
  c^{((N-1)K+1)} & \geq & \cdots & \geq & c^{(NK)}\\
  \downarrow &  & \downarrow &  &  &  & \downarrow &  &  &  & \downarrow & & & & 
  \downarrow \\
  \gamma^{(1)} &  & \gamma^{(2)} &  & \cdots &  & \gamma^{(j)} &  & \cdots &  & 
  \gamma^{((N-1)K+1)}& &\cdots &  & \gamma^{(NK)}\\\cline{1-7}
\end{array} 
$

\end{document}

enter image description here