/*
 * data structure - organizing data into a structure
 * functions - add delete transfer
 * search, print
 * If she asks to create a class stack, a class queue, as functions know the functions
 * Add delete search print sort
 * how can we identfiy the private data structure (under private keyword)
 * what is an array (size, pointer to first)
 * stack - last in first out,
 * queue - first in first out
 * know at least what is data strucutre (stucturing data within memory)
 * how to add/remove data structure, search data structure
 * how to solve/sort data structure
 * sorting is also one kind of question which can be built in
 * where can stack be used and what is it?
 * basic operations: push, pop, peek
 * applications: infix, postfix, reverse a string, implement two stacks inan array, check for balanced parenthesis
 * What is a queue and how is it implemented?
 * enqueue, dequeue, front, rear
 *
 * Exam 2:
 * p1 stack: 40
 *  -convert infix to postfix conversion using stack (by hand not prog) (5 pts)
 *  - evaluation of postfix expression (by hand not prog) (5 pts)
 *  - write a function on a stack ( 10 pts) - Use the stack functions, but write function to do this with stack
 *  - write a function on a stack(10 pts)
 *  - what is the output (10 pts)
 *  //unless it changes whole function, won't penalize for curly brackets (do not trust this)
 *  //look at stuff on geeksforgeeks
 *  //dont spend forever on it, its 10 points
 *  //check the examples on url on access
 *  //focus on stuff everybody can do, but you need to know logic - have a solid background in logic
 *  //example: add two numbers from two stacks, decide where to put the result
 *  //example: reverse queue, union of two queues
 *  //for whats the output: every time you see cout, cout it, unless its about content of stacks

 *
 *
 * p2 queue: 40 //all queues: circular, priority
 * 1. what is the output of queue (10)//will be tricky, will give you queue, will play with remove/add, then give contents of queue
 * 2. whats inside the queue after running a code(10)
 * 3. write a function using queue(10)
 * 4. write a function using queue(10) //she doesn't seem to know if she will alter this question string to use abnormal functions
 * //direct function on queue: enque, deque, search, (have question on binary search, may change)
 * //may ask sorting, but not testing on sorting. Can use any sort.
 * //will not ask efficiency questions
 * //you can do linear search or binary search for sorts and stuff, dont need exactly insertion sort
 * //study insertion sort, she recommends
 * //probably linkedlists
 * //keep in mind as general: insertion sort, templates
 * //declare a queue, use head as front
 * //for example, write a function to print a queue
 * //if she gives you header, you have to use queue as template. in this case, since its not clear, you can do queue->front
 * //if you did queue.front, she would consider it right.
 * //if you write a function to get the front, which returns the first element, all correct
 * //try not to do a lot of lines
 * //queue is popular for interviews
 * //example questions: traversal ,reverse, etc. She is focusing on Questions not from class.
 * //difference between sorted and unsorted array, can stop with while if sorted
 * //otherwise forloop
 * //find smallest/largest in a (queue, stack, etc)
 * // heapsort is popular on interview question (??)
 * // linkedlist or arrays for stacks or queues,
 * //will send preassessment Sunday night
 * p3 recursion: 20 points
 *1 - implement function iteartively as recursion(5,5)
 * 2 - Like clicker quiz (5 points )(may be taken directly from clicker) (recursion in general, not stack or queue or stuff)
 * 3 - convert function interatively, recursively (5 points) (loop to recurs, other wy) (may involve queue/stack)
 * //easy question: how to print recusrively
 * //stack backwards, forward, queue back, forward
 * //search for number, traverse (print), if asked sorting do anything mainly insertion, templates
 * //data structure interview questions
 * //queue implementation using linked list
 * //ultimately if you have to traverse a queue as a linkedlist, you can. You have a pointer, rule says first end first out,
 * //try to write something to traverse
 * //try to find the next greater element in a queue
 * //previous and next in queue, sort it, 2nd from rear that kind of thing
 * //instead of taking n times, sort in decreasing order
 * //how do you approach it?
 * //can you find next greater in a stack
 * //sort it, put it in another array, only remove top at time
 * //don't panic, you can have your own idea
 * //respect definition of stack
 * //if you don't have to violate it, do it
 * aws: amazon web services, you create your website, queue for messages, queue for requests,
 * if you have a popular website, and he can't answer all of it, he has a timeline
 * if request is not answered in 4 days, drop message and answer other message
 * one queue, different type of messages, if message is informational, you don't have to do anything, then drop
 * if request, put it in another queue, goes to server, if this service is very long or doesn't have time after 4 days
 * circular queue, or put in another queue
 * if it takes more than a week, drop it completely and resubmit it
 * amazon web services
 * Amazon Simple Queue Service
 * exact order they are sent
 * create one queue, have timer for four days, type of message and message, and if informational, read and drop, if
 * request, executed. Highest priority versus long message are requests
 * Example: aws, one queue 2 types, message I, message R, assume every minute 3 messages,
 * After 4 hours, the untreated request enqueuer with highest priority
 * Mi, Mr, Mr, Mi, Mr, Mr, Mi,
 * At hour 4:
 * mr, mr, mi, mr, mr, mi (old queue), mr, mi, mi, mr
 * after 4 hours, if still in queue, we still get other request
 * remove them, put them at end of queue
 * after two hours, he finds out he never reached one of the big ones, he drops it completely, and asks user to resubmit
 *