Question 1

A stack based on a linked list is based on the following code
Class Node{
String element;
Node next;
Node(String el,Node n){
Element = el;
Next = n;
}
}
Node top = null;
The code for implementing the String pop()operation is

Accepted Answer

A)   if (top != null) {Top = top.next;String el = top.element;Return el;}Else throw new RuntimeException("Empty Stack") ;
B)   if (top != null.{String el = top.element;Top = top.next;Return el;}Else throw new RuntimeException("Empty Stack".;
C)   if (top != null.{String el = top.element;Top = null;Return el;}Else throw new RuntimeException("Empty Stack".;
D)   return top.element;Top = top.next; B

Question 2

A queue based on a linked list uses the following code
Class Node{
String element;
Node next;
Node (String el,Node n){
Element = el;
Next = n;
}
}
Node front = null,rear = null;
What is the right code for String remove()operation? Such an operation removes and returns an element from the queue.

Accepted Answer

A)   if (rear== null) Throw new RuntimeException("Empty") ;String temp = rear.element;Rear = rear.next;If (front == null) Rear = null;Return temp;
B)   if (front == rear.Throw new RuntimeException("Empty".;String temp = front.element;Front = front.next;If (front == null.Rear = null;Return temp;
C)   if (front == null.Throw new RuntimeException("Empty".;String temp = front.element;Front = front.next;If (front == null.Front = rear;Return temp;
D)   if (front == null.Throw new RuntimeException("Empty".;String temp = front.element;Front = front.next;If (front == null.Rear = null;Return temp; D

Question 3

In a list implementation of a queue,the end of the list from which elements are removed is called

Accepted Answer

A)   the front of the queue
B)   the rear of the queue
C)   the top of the queue
D)   the bottom of the queue A

Question 4

The stack pull operation

Accepted Answer

A)   increases the capacity of a stack that is about to fill up
B)   extracts one element from the stack and returns it
C)   brings two stacks together and combines their elements
D)   does not exist: There is no such stack operation

Question 5

The stack peek operation

Accepted Answer

A)   checks a stack to see if there are any elements in it
B)   removes and returns an item from the stack
C)   returns the item at the top of the stack,but does not remove it
D)   adds a single item to the stack

Question 6

Consider a class that uses the following variables to implement an array-based stack:
String [ ] s = new String[100];
Int top = -1;// Note top == -1 indicates stack is empty
A method that implements a String pop()operation can be written as

Accepted Answer

A)   if (top == -1) Throw new RuntimeException("Empty Stack") ;Top --;String temp = s[top];S[top] = null;Return temp;
B)   if (top == -1.Throw new RuntimeException("Empty Stack".;S[top] = null;Top--;Return s[top ];
C)   if (top == -1.Throw new RuntimeException("Empty Stack".;String temp = s[top];S[top] = null;Top--;Return temp;
D)   None of the above

Question 7

A queue is a container that allows elements to be stored and removed

Accepted Answer

A)   in a last-in-first-out fashion
B)   in a first-in-first-out fashion
C)   in a first-in-last-out fashion
D)   quickly and efficiently

Question 8

Consider a class that uses the following variables to implement an array-based stack:
String [ ] s = new String[100];
Int top = 0;
A method that implements the String peek()operation can be written as

Accepted Answer

A)   return s[top];
B)   if (top == 0.Throw new RuntimeException("Underflow".;ElseReturn s[top];
C)   if (top == 0.Throw new RuntimeException("Underflow".;ElseReturn s[top-1];
D)   return s[top-1];

Question 9

Consider a class that uses the following variables to implement an array-based stack:
String [ ] s = new String[100];
Int top = 0;
A method for adding an item x to the stack can be written as

Accepted Answer

A)   s.add(top,x) ;
B)   if (top == s.length.Throw new RuntimeException("Overflow".;Else{Top ++;S[top] = x;}
C)   if (top S[top] = x;Top ++;
D)   if (top {S[top] = x;Top ++;}ElseThrow new RuntimeException("Overflow".;

Question 10

In an implementation of a stack based on a singly-linked list,it is most efficient to add a new item so that

Accepted Answer

A)   the new item has the highest index of all items in the list
B)   the new item has the lowest index of all items in the list
C)   the new item is not duplicated by any other item already in the stack
D)   the items in the stack stay sorted in ascending order

Question 11

A queue based on a linked list uses the following code
Class Node{
String element;
Node next;
Node (String el,Node n){
Element = el;
Next = n;
}
}
Node front = null,rear = null;
What is the right code for the boolean empty()method?

Accepted Answer

A)   return front == null;
B)   if (rear == front.return true;ElseReturn false;
C)   if (front == null.Throw new RuntimeException("Empty".;ElseReturn false;Return true;
D)   return front == rear;

Question 12

In a list implementation of a stack,the end of the list at which elements are added and removed is called

Accepted Answer

A)   the active end of the stack
B)   the head of the stack
C)   the top of the stack
D)   the bottom of the stack

Question 13

Compilers of modern programming languages support method calls and returns with an internal

Accepted Answer

A)   priority queue
B)   hash set
C)   stack
D)   queue

Question 14

Consider a class that uses the following variables to implement an array-based stack:
String [ ] s = new String[100];
Int top = -1;// Note top == -1 indicates stack is empty
A method that implements a String peek()operation can be written as

Accepted Answer

A)   if (top == -1) Throw new RuntimeException("Empty Stack") ;ElseReturn s[top -1];
B)   if (top > -1.Return s[top];ElseThrow new RuntimeException("Empty Stack".;
C)   top --;If (top == -1.Throw new RuntimeException("Empty Stack".;ElseReturn s[top];
D)   if (top == 0.Throw new RuntimeException("Empty Stack".;Else{Top --;Return s[top];}

Question 15

In an array-based implementation of a stack,an operation that needs to add a new element to the stack may not be able to complete because the array is full.In this case,the failed operation should

Accepted Answer

A)   print an error message and return from the method
B)   throw some appropriately defined exception
C)   print an error message and exit
D)   alert the user before continuing execution

Question 16

The JCF Stack class is used to instantiate a stack:
Stack intStack = new Stack();
The statements
Int k = 77;
IntStack.push(k*k);
Use the primitive type int instead of the wrapper type Integer.These statements

Accepted Answer

A)   cause a compile time error
B)   compile and execute correctly
C)   cause a ClassCastException
D)   None of the above

Question 17

A stack is a container that allows elements to be stored and removed

Accepted Answer

A)   in a last-in-first-out fashion
B)   in a first-in-first-out fashion
C)   last-in-last-out fashion
D)   according to priority

Question 18

A stack based on a linked list is based on the following code
Class Node{
String element;
Node next;
Node(String el,Node n){
Element = el;
Next = n;
}
}
Node top = null;
The code for implementing the String peek()operation is

Accepted Answer

A)   String temp = top.element;If (temp != null) return temp;ElseThrow new RuntimeException("Empty Stack") ;
B)   if (top != null.Return top.element;Else return top.next;
C)   if (top != null.Return top.elementElseThrow new RuntimeException("Empty Stack".;
D)   if (top != null.Return top;

Question 19

The operation for removing an item from a queue is called

Accepted Answer

A)   enqueue
B)   dequeue
C)   extract
D)   disqueue

Question 20

The stack pop operation

Accepted Answer

A)   removes all items currently on the stack
B)   extracts one element from the stack and returns it
C)   removes from the stack the number of elements specified by its integer parameter
D)   does not exist: There is no such stack operation

Exam 21: Stacks and Queues

A stack based on a linked list is based on the following code Class Node{ String element; Node next; Node(String el,Node n) { Element = el; Next = n; } } Node top = null; The code for implementing the String pop() operation is

A queue based on a linked list uses the following code Class Node{ String element; Node next; Node (String el,Node n) { Element = el; Next = n; } } Node front = null,rear = null; What is the right code for String remove() operation? Such an operation removes and returns an element from the queue.

In a list implementation of a queue,the end of the list from which elements are removed is called

The stack pull operation

The stack peek operation

Consider a class that uses the following variables to implement an array-based stack: String [ ] s = new String[100]; Int top = -1;// Note top == -1 indicates stack is empty A method that implements a String pop() operation can be written as

A queue is a container that allows elements to be stored and removed

Consider a class that uses the following variables to implement an array-based stack: String [ ] s = new String[100]; Int top = 0; A method that implements the String peek() operation can be written as

Consider a class that uses the following variables to implement an array-based stack: String [ ] s = new String[100]; Int top = 0; A method for adding an item x to the stack can be written as

In an implementation of a stack based on a singly-linked list,it is most efficient to add a new item so that

A queue based on a linked list uses the following code Class Node{ String element; Node next; Node (String el,Node n) { Element = el; Next = n; } } Node front = null,rear = null; What is the right code for the boolean empty() method?

In a list implementation of a stack,the end of the list at which elements are added and removed is called

Compilers of modern programming languages support method calls and returns with an internal

Consider a class that uses the following variables to implement an array-based stack: String [ ] s = new String[100]; Int top = -1;// Note top == -1 indicates stack is empty A method that implements a String peek() operation can be written as

In an array-based implementation of a stack,an operation that needs to add a new element to the stack may not be able to complete because the array is full.In this case,the failed operation should

The JCF Stack class is used to instantiate a stack: Stack< Integer > intStack = new Stack< Integer >() ; The statements Int k = 77; IntStack.push(k*k) ; Use the primitive type int instead of the wrapper type Integer.These statements

A stack is a container that allows elements to be stored and removed

A stack based on a linked list is based on the following code Class Node{ String element; Node next; Node(String el,Node n) { Element = el; Next = n; } } Node top = null; The code for implementing the String peek() operation is

The operation for removing an item from a queue is called

The stack pop operation