Function $4$: concatenate$($llst$1,$ llst$2)$

Given two $($possibly empty$)$ linked lists, concatenate them such that the first list comes first.

Example: When the first input linked list lst$1$ is $1->2->3$ and the second lst$2$ is $7->8->9,$ the output linked list

is $1->2->3->7->8->9.$

std::list concatenate$($const std::list& list$1,$ const std::list& list$2)\{$

$//$ TODO: Student to implement

return std::list$()$; $//$ Placeholder return

$\}$

#ifndef HW$3\_$H

#define HW$3\_$H

#include

#include

#include

#include

float postfixEval$($const std::vector& tokens$)$;

bool validParentheses$($const std::string& s$)$;

class Stack$2\{$

public:

void push$($int x$)$;

void pop$()$;

int top$()$;

bool empty$()$;

private:

std::queue queue$1,$ queue$2$;

$\}$;

std::list concatenate$($const std::list& list$1,$ const std::list& list$2)$;

std::list removeNodesFromBeginning$($std::list& list, int n$)$;

std::list removeNodes$($std::list& list, int i$,$ int n$)$;

void buildHeap$($std::vector& arr$)$;

#endif $//$HW$3\_$H