To write a breadth$-$first traversal for a Top$-$Down Tree, we need to modify the provided code and implement the $`$breadthFirstTraversal$`$ function. The modified code will be:

#include

#include $"$TD$\_$Tree.h$"$

int preceed$($const char& c$1,$ const char& c$2)\{$

return c$1-$ c$2$;$\}$

void dump$($char & value$)\{$

std::cout $<<$ value;

$\}$

template

void breadthFirstTraversal$($TDTree& tree, void $(*$processNode$)($T& value$))\{$

if $($tree$.$isEmpty$())\{$

return;

$\}$

Queue$*>$ queue;

queue.enqueue$($tree$.$getRoot$())$;

while $(!$queue.isEmpty$())\{$

Node$*$ current $=$ queue.dequeue$()$;

processNode$($current$->$data$)$;

for $($Node$*$ child : current$->$children$)\{$

queue.enqueue$($child$)$;

$\}$

$\}$

$\}$

int main$()\{$

TDTree tree$($preceed$)$;

tree.add$(\text{'}$H$\text{'},\text{'}$H$\text{'},1)$;

tree.add$(\text{'}$H$\text{'},\text{'}$i$\text{'},1)$;

tree.add$(\text{'}$i$\text{'},\text{'}1\text{'},1)$;

tree.add$(\text{'}$H$\text{'},\text{'}$t$\text{'},2)$;

tree.add$(\text{'}$t$\text{'},\text{'}$h$\text{'},1)$;

tree.add$(\text{'}$t$\text{'},\text{'}$r$\text{'},2)$;

tree.add$(\text{'}$t$\text{'},\text{'}$e$\text{'},3)$;

tree.add$(\text{'}$h$\text{'},\text{'}$E$\text{'},1)$;

std::cout $<<$ "Tree printing breadth first traversal:

$"$;

breadthFirstTraversal$($tree$,$ dump$)$;

std::cout $<<$ std::endl $<<$ std::endl;

return $0$;

$\}$ Please I Need The TD$\_$Tree.h header file code isn't working for my side