$//$ DO NOT INCLUDE ANY OTHER LIBRARIES$/$FILES

#include "pointer.h$"$

$/////////////////////////////////////////////////////////////////$

$//////////////////////////////////////////////////$

$//$ In this assignment, you can assume that function parameters

are valid and the memory is managed by the caller $//$

$/////////////////////////////////////////////////////////////////$

$//////////////////////////////////////////////////$

$//$ Returns the area of a rectangle

$//$ The shape is guaranteed to be a valid rectangle

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

$\{$

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

$//$ IMPLEMENT THIS

return $0$;

$\}$

$//$ Returns the area of an equilateral triangle

$//$ The shape is guaranteed to be a valid triangle

$//$ The area of an equilateral triangle is sqrt$(3)/4$ times length

squared

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

$\{$

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

$//$ IMPLEMENT THIS

return $0$;

$\}$

$//$ Returns the perimeter of a rectangle

$//$ The shape is guaranteed to be a valid rectangle

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

$\{$

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

$//$ IMPLEMENT THIS

return $0$;

$\}$

$//$ Returns the perimeter of an equilateral triangle

$//$ The shape is guaranteed to be a valid triangle

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

$\{$

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

$//$ IMPLEMENT THIS

return $0$;

$\}$

$//$ Initializes a rectangle shape

void rectangle$\_$construct$($rectangle$\_$t$*$ shape, const char$*$ name,

double width, double length$)$

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$ Initializes a triangle shape

void triangle$\_$construct$($triangle$\_$t$*$ shape, const char$*$ name,

double length$)$

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$ Compares the area of shape$1$ with shape$2$

$//$ Returns $-1$ if the area of shape$1$ is less than the area of

shape$2$

$//$ Returns $1$ if the area of shape$1$ is greater than the area of

shape$2$

$//$ Returns $0$ if the area of shape$1$ is equal to the area of shape$2$

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

$\{$

$//$ IMPLEMENT THIS

return $0$;

$\}$

$//$ Compares the perimeter of shape$1$ with shape$2$

$//$ Returns $-1$ if the perimeter of shape$1$ is less than the

perimeter of shape$2$

$//$ Returns $1$ if the perimeter of shape$1$ is greater than the

perimeter of shape$2$

$//$ Returns $0$ if the perimeter of shape$1$ is equal to the perimeter

of shape$2$

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

$\{$

$//$ IMPLEMENT THIS

return $0$;

$\}$

$//$

$//$ Linked list functions

$//$

$//$ Initializes a singly linked list

$//$ If compare is NULL, the list is unsorted and new nodes are

inserted at the head of the list

$//$ If compare is not NULL, the list is sorted in increasing order

based on the comparison function

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

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$ Inserts a node into the linked list based on the list

comparison function

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

node$)$

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$ Removes all nodes from the linked list containing the given

shape

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

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$

$//$ Tree iterator functions

$//$

$//$ Initializes an iterator to the beginning of a tree $($i$.$e$.,$

first in$-$order node$)$

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

root$)$

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$ Updates an iterator to move to the next in$-$order node in the

tree if possible

$//$ Moving past the last in$-$order node in the tree results in the

iterator reaching a NULL state representing the end of the tree

void tree$\_$iterator$\_$next$($tree$\_$iterator$\_$t$*$ iter$)$

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$ Returns true if iterator is at the end of the tree or false

otherwise

$//$ The end of the tree is the position after the last in$-$order

node in the tree $($i$.$e$.,$ NULL state from tree$\_$iterator$\_$next$)$

bool tree$\_$iterator$\_$at$\_$end$($tree$\_$iterator$\_$t$*$ iter$)$

$\{$

$//$ IMPLEMENT THIS

return false;

$\}$

$//$ Returns the current node that the iterator references or NULL

if the iterator is at the end of the tree

tree$\_$node$\_$t$*$ tree$\_$iterator$\_$get$\_$node$($tree$\_$iterator$\_$t$*$ iter$)$

$\{$

$//$ IMPLEMENT THIS

return NULL;

$\}$

$//$ Returns the current shape that the iterator references or NULL

if the iterator is at the end of the tree

shape$\_$t$*$ tree$\_$iterator$\_$get$\_$shape$($tree$\_$iterator$\_$t$*$ iter$)$

$\{$

$//$ IMPLEMENT THIS

return NULL;

$\}$

$//$

$//$ Tree analysis functions

$//$

$//$ Returns the maximum, minimum, and average area of shapes in

the tree

$//$ An empty tree should not modify the maximum, minimum, or

average

void max$\_$min$\_$avg$\_$area$($tree$\_$node$\_$t$*$ root, double$*$ max, double$*$

min, double$*$ avg$)$

$\{$

$//$ IMPLEMENT THIS

$\}$

$//$ Executes the func function for each node in the tree in$-$order

$//$ The function takes in an input data and returns an output

data, which is used as input to the next call to the function

$//$ The initial input data is provided as a parameter to foreach,

and foreach returns the final output data

$//$ For example, if there are three nodes, foreach should behave

like: return func$($node$3,$ func$($node$2,$ func$($node$1,$ data$)))$

double foreach$($tree$\_$node$\_$t$*$ root, foreach$\_$fn func, double data$)$

$\{$

$//$ IMPLEMENT THIS

return $0$;

$\}$