Use the stack in following code to implement the converting of a given postfix expression into infix

expression.

$/**$ Linked stack implementation $*/$

class IStack implements Stack $\{$

private Link top;

$//$ Pointer to first element

private int size:

$//$Number of elements

$/**$ Constructors $*/$

public LStack$()\{$ top $=$ null; size $=0$;$\}$

public LStack $($int size$)$

$\{$top $=$ null; size $=0$;$\}$

$/**$ Reinitialize stack $*/$

public void clear$()\{$top $=$ null; size $=0$;$\}$

$/**$ Put $"$it$"$ on stack $*/$

public void push $($E it$)\{$

top $=$ new Link $($it$,$ top$)$;

size$++$;$\}$

$/**$ Remove $"$it$"$ from stack$*/$

public E pop$()\{$

assert top $!=$ null: "Stack is empty";

E it $=$ top.element $()$;

top $=$top.next $()$;

size$--$;

return it;$\}$

$/**$ @return Top value $*/$

public E topvalue $()\{$

assert top $!=$ null:"Stack is empty";

return top.element$()$;$\}$

$/**$ @return Stack length $*/$

public int length$()\{$

return size;$\}$