Select the correct answerUsingPop(S1, Item)Push(S1,Item)Read(Item)Print(Item)the variables S1 represents (stack) and Item are given the input file:A,B,C,D,E,F <EOF>Which stacks are possible:Options5    A4    B3    C2    D1    E54  3   F2   D1   B543   C2   E1   B5  4  3   D2   A1   FFinish ClearPrev

Select the correct answerUsing Pop (S1,Item) ,Push(S1, Item), Getlist(Item), Pop(S2,Item), and the variables S1,S2(stacks with Top1 and Top2) and Item and given the input file: A,B,C,D,E,F Which stack are possible?OptionsAll possible stacks with A,B,C,D,E and FExact and only those stacks which can be produced with S1 aloneTwice as many stacks as can be produced with S1 aloneNo possible stacks with A,B,C,D,E and F

Objectives - Learn stacksUsing ArrayCreate a program to implement a stack by using array1) You have to get the user choice using keyboard as follows in the main functionChoices1. Push2. Pop3. Print all the elements of the stack4. Print the top element of the stack5. Exit2) Implement functions one by one according to each choice3) Using a switch case complete the code.Using Linked-listDo the above exercise using singly linked list

Select the correct answerA stack is implemented with an array of 'A [0..N - 1]' and a varlable 'pos'. The push and pop operations are defined by the following code.push(x) A[pos] ← X pos ← pos - 1end pushpop( ) pos ← pos + 1 return A[pos]end popWhich of the following will initialize an empty stack with capacity N for the above Implementation?Optionspos ← −1pos ← 1pos ← N−1pos

Problem Statement:Write a program that implements the Stack Data structure using ArraysThe operations performed on the Stack arePushPopPeekInput format:The first line of input contains the number of operations to be performed on the stackThe next lines contain the integers separated by space in which the first integer indicates the operation to be performed and the second integer contains the element to be pushed.1 ---> indicates the Push2 ---> indicates the Pop3 ---> indicates the PeekOutput format:Display every element after performing the peek operationDisplay the stack after performing all operations at the end.Sample Test Case:Input:61 21 31 4231 5Output:35 3 2Explanation:1 2 ---> 2 will be pushed1 3 ---> 3 will be pushed1 4 ---> 4 will be pushed2 ---> Last element(4) is popped3 ---> peek operation is performed which results in printing the top element of the stack i.e 31 5 ---> 5 will be pushed6 Operations are completedTherefore one peek operation is performed so the output is 3 and the final stack 5 3 2Note:If the stack is empty and when pop and peek are performed first, proceed to the next operation without displaying and modifying anything in the stack.If the stack is empty and nothing is pushed to the stack, Print Empty at the end.Sample Test CasesTest Case 1:Expected Output:61 21 31 4231 535·3·2

A stack is implemented using an array and the top is always pointing to the first position in the array. Assuming the stack is not empty, the time complexities of push() and pop() operations are:Group of answer choicesO(n) and O(1)O(n) and O(n)O(1) and O(n)O(1) and O(1)