$\Huge{\LaTeX 真正的用法}$

$$\newcommand\sss[1]{ \Huge{\begin{matrix} \bold数&\bold据\cr \bold结&\bold构 \end{matrix}} } \newcommand\write[1]{ {#1}\quad\mathop{\sss{}}\limits_{_{#1}}^{^{#1}}\quad{#1} } \sss{}\\ \write{\sss{}}\\ \write{\write{\sss{}}}\\ \write{\write{\write{\sss{}}}}\\ $$$$\newcommand\sss[1]{ \Huge{\begin{matrix} \bold数&\bold据\cr \bold结&\bold构 \end{matrix}} } \newcommand\write[1]{ {#1}\quad\mathop{\sss{}}\limits_{_{#1}}^{^{#1}}\quad{#1} } \write{\write{\write{\write{\sss{}}}}}\\ $$

$\newcommand\write[1]{{#1}_{\,#1}^{\,#1}}\newcommand\str{\Huge\bold{高级^{^数_据}_{^结_构}}}\str\\\write{\str}\\\write{\write{\str}}\\\write{\write{\write{\str}}}\\\write{\write{\write{\write{\str}}}}$

$\newcommand\alln[2]{\begin{matrix}#1 & #2 \cr#2 & #1 \end{matrix}}\newcommand\allr[2]{\begin{matrix}#2 & #1 \cr#1 & #2 \end{matrix}}\newcommand\fl{\alln{+}{-}}\newcommand\fr{\allr{+}{-}}\alln{\alln{\alln{\alln{\fl}{\fr}}{\allr{\fl}{\fr}}}{\allr{\alln{\fl}{\fr}}{\allr{\fl}{\fr}}}}{\allr{\alln{\alln{\fl}{\fr}}{\allr{\fl}{\fr}}}{\allr{\alln{\fl}{\fr}}{\allr{\fl}{\fr}}}}$

造一个“铁路”： $\newcommand\write[1]{{#1}{#1}}\write{\write{\write{\write{\write{{\write{\write{\write{\write{\sout{\ \ \ \ \ \ \ \ }}}}}}}}}}}$ $\newcommand\write[1]{{#1}{#1}}\write{\write{\write{\write{\write{{\write{\write{\write{\write{\Rightarrow\ \ \ \ }}}}}}}}}}$ $\newcommand\write[1]{{#1}{#1}}\write{\write{\write{\write{\write{{\write{\write{\write{\write{\sout{\ \ \ \ \ \ \ \ }}}}}}}}}}}$ 造两个“铁路”：

$\newcommand\write[1]{\begin{matrix}{#1}\cr{#1}\end{matrix}}\write{\write{\write{\write{\write{\write{\write{\write{|\Downarrow|}}}}}}}}$

$\newcommand\write[1]{\begin{matrix}{#1}\cr{#1}\end{matrix}}\write{\write{\write{\write{\write{\write{\write{\write{|\Downarrow|}}}}}}}}$

$\newcommand\write[1]{\begin{matrix}{#1}\cr{#1}\end{matrix}}\write{\write{\write{\write{\write{\write{\write{\write{|\Downarrow|}}}}}}}}$

$|车\ |$

$\sout{\ \ \ \ \ \ \ }$