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Step$-1$

Define the Structures $($Assumed from the Context$)$

First, let's assume the structures for rectangle$\_$t$,$ triangle$\_$t$,$ and shape$\_$t based on the context:First, let's assume the structures for rectangle$\_$t$,$ triangle$\_$t$,$ and shape$\_$t based on the context. This is the place where it is determined the parameters. For example, length, width, area, perimeter, etc.

Code:

typedef struct $\{$

const char $*$name;

double width;

double length;

$\}$ rectangle$\_$t;

typedef struct $\{$

const char $*$name;

double length;

$\}$ triangle$\_$t;

typedef struct $\{$

const char $*$name;

double area;

double perimeter;

$\}$ shape$\_$t;

Step$-2$

Implement the Functions:

Calculate Area of Rectangle:

In this case those functions are put that are utilized to Calculate the Area of Rectangle.

Code:

#include "pointer.h$"$

double rectangle$\_$area$($void $*$shape$)\{$

rectangle$\_$t $*$rectangle $=($rectangle$\_$t $*)$ shape;

return rectangle$->$width $*$ rectangle$->$length;

$\}$

Calculate Area of Equilateral Triangle

In this case those functions are put that are utilized to Calculate Area of Equilateral Triangle.

Code:

double triangle$\_$area$($void $*$shape$)\{$

triangle$\_$t $*$triangle $=($triangle$\_$t $*)$ shape;

return $($sqrt$(3)/4)*($triangle$->$length $*$ triangle$->$length$)$;

$\}$

double rectangle$\_$perimeter$($void $*$shape$)\{$

rectangle$\_$t $*$rectangle $=($rectangle$\_$t $*)$ shape;

return $2*($rectangle$->$width $+$ rectangle$->$length$)$;

$\}$

double triangle$\_$perimeter$($void $*$shape$)\{$

triangle$\_$t $*$triangle $=($triangle$\_$t $*)$ shape;

return $3*$ triangle$->$length;

$\}$

Calculate Perimeter of Rectangle:

In this case those functions are put that are utilized to Calculate Perimeter of Rectangle.

double rectangle$\_$perimeter$($void $*$shape$)\{$

rectangle$\_$t $*$rectangle $=($rectangle$\_$t $*)$ shape;

return $2*($rectangle$->$width $+$ rectangle$->$length$)$;

$\}$

Calculate Perimeter of Equilateral Triangle:

In this case those functions are put that are utilized to Calculate Perimeter of Equilateral Rectangle

Code:

double triangle$\_$perimeter$($void $*$shape$)\{$

triangle$\_$t $*$triangle $=($triangle$\_$t $*)$ shape;

return $3*$ triangle$->$length;

$\}$

Initialize Rectangle Shape:

Now, it is initialized to form the rectangle shape.

Code:

void rectangle$\_$construct$($rectangle$\_$t $*$shape$,$ const char $*$name$,$ double width, double length$)\{$

shape$->$name $=$ name;

shape$->$width $=$ width;

shape$->$length $=$ length;

$\}$

Initialize Triangle Shape:

Now, it is initialized to form the triangle shape.

Code:

void triangle$\_$construct$($triangle$\_$t $*$shape$,$ const char $*$name$,$ double length$)\{$

shape$->$name $=$ name;

shape$->$length $=$ length;

$\}$

Step $3$

Compressing the Functions:

Compare Shapes by Area

Now the shapes are compress by the size of their area.

Code:

int compare$\_$by$\_$area$($shape$\_$t $*$shape$1,$ shape$\_$t $*$shape$2)\{$

if $($shape$1->$area $<$ shape$2->$area$)\{$

return $-1$;

$\}$ else if $($shape$1->$area $>$ shape$2->$area$)\{$

return $1$;

$\}$ else $\{$

return $0$;

$\}$

$\}$

Compare Shapes by Perimeter

Now, the shapes are compressed by their perimeters.

Code:

int compare$\_$by$\_$perimeter$($shape$\_$t $*$shape$1,$ shape$\_$t $*$shape$2)\{$

if $($shape$1->$perimeter $<$ shape$2->$perimeter$)\{$

return $-1$;

$\}$ else if $($shape$1->$perimeter $>$ shape$2->$perimeter$)\{$

return $1$;

$\}$ else $\{$

return $0$;

$\}$

$\}$

Step$-4$

Initialize a Singly Linked List

The single linked list is initialized here:

Code:

void linked$\_$list$\_$init$($linked$\_$list$\_$t $*$list$,$ compare$\_$fn compare$)\{$

list$->$head $=$ NULL;

list$->$compare $=$ compare;

$\}$

Insert a Node into the Linked List

Now, a node is inserted into the linked list.

Code:

void linked$\_$list$\_$insert$($linked$\_$list$\_$t $*$list$,$ linked$\_$list$\_$node$\_$t $*$node$)\{$

if $($list$->$compare $==$ NULL$)\{$

node$->$next $=$ list$->$head;

list$->$head $=$ node;

$\}$ else $\{$

linked$\_$list$\_$node$\_$t $**$current $=$ &list$->$head;

while $(*$current $!=$ NULL && list$->$compare$((*$current$)->$shape, node$->$shape$)<0)\{$

current $=$ &$(*$current$)->$next;

$\}$

node$->$next $=*$current;

$*$current $=$ node;

$\}$

$\}$

Remove Nodes from the Linked List Containing the Given Shape

Now it is removed the nodes from the Linked List Containing the Given Shape

Code:

void linked$\_$list$\_$remove$($linked$\_$list$\_$t $*$list$,$ shape$\_$t $*$shape$)\{$

linked$\_$list$\_$node$\_$t $**$current $=$ &list$->$head;

while $(*$current $!=$ NULL$)\{$

if $((*$current$)->$shape $==$ shape$)\{$

linked$\_$list$\_$node$\_$t $*$to$\_$remove $=*$current;

$*$current $=(*$current$)->$next;

free$($to$\_$remove$)$;

$\}$ else $\{$

current $=$ &$(*$current$)->$next;

$\}$

$\}$

$\}$

Step$-5$

Tree Iterator Functions

Initialize Tree Iterator

Now, the tree iterator functions are defined and initialized.

Code:

void tree$\_$iterator$\_$begin$($tree$\_$iterator$\_$t $*$iter$,$ tree$\_$node$\_$t $*$root$)\{$

iter$->$root $=$ root;

iter$->$current $=$ NULL;

$//$ Allocate stack with initial capacity

iter$->$stack$\_$capacity $=100$; $//$ Adjust the capacity as needed

ite