Deck 18: Searching and Sorting Algorithms

Question 1

The selection sort algorithm finds the location of the smallest element in the unsorted portion of the list.

Answer 1

True

Question 2

The sequential search algorithm uses a(n)____ variable to track whether the item is found.

A) int
B) bool
C) char
D) double

Answer 2

B

Question 3

Consider the following list: int list[] = {4,8,19,25,34,39,45,48,66,75,89,95}
When performing a binary search for 75,after the first comparison,the search is restricted to ____.

A) list[0]...list[6]
B) list[0]...list[7]
C) list[5]...list[11]
D) list[6]...list[11]

Answer 3

D

Question 4

A sequential search of an n-element list takes ____ key comparisons if the item is not in the list.

A) 0
B) n/2
C) n
D) n2

Question 5

During the sorting phase of insertion sort,the array containing the list is divided into two sublists,sorted and unsorted.

Question 6

Suppose that L is a sorted list of size 1024,and we want to determine whether an item x is in L.From the binary search algorithm,it follows that every iteration of the while loop cuts the size of the search list by half.

Question 7

During the second iteration of a selection sort,the smallest item is moved to the top of the list.

Question 8

A sequential search of an n-element list takes ____ key comparisons on average to determine whether the search item is in the list.

A) 0
B) n/2
C) n
D) n2

Question 9

The swap function of quick sort is written differently from the swap function for selection sort.

Question 10

With the binary search algorithm,____ key comparison(s)is/are made in the successful case-the last time through the loop.

A) one
B) two
C) n-2
D) n

Question 11

The sequential search algorithm does not require that the list be sorted.

Question 12

The binary search algorithm can be written iteratively or recursively.

Question 13

In the average case,sequential search typically searches ____.

A) one quarter of the list
B) one third of the list
C) one half of the list
D) the entire list

Question 14

In a binary search,first,the search item is compared with the last element of the list.

Question 15

Consider the following list: int list[] = {4,8,19,25,34,39,45,48,66,75,89,95}
When performing a binary search,the target is first compared with ____.

A) 4
B) 25
C) 39
D) 95

Question 16

In a bubble sort,the smaller elements move toward the bottom,and the larger elements move toward the top of the list.

Question 17

After the second iteration of bubble sort for a list of length n,the last ____ elements are sorted.

A) two
B) three
C) n-2
D) n

Question 18

If n = 1000,then to sort the list,selection sort makes about 50,000 key comparisons.

Question 19

In a bubble sort for list of length n,the first step is to compare elements ____.

A) list[0] and list[n]
B) list[0] and list[n-1]
C) list[0] and list[1]
D) list[n-1] and list[n+1]

Question 20

The formula to find the index of the middle element of a list is ____.

A) (mid + last)/2
B) (first + last) - 2
C) (first + last) / 2
D) (first + mid ) * 2

Question 21

Assume that list consists of the following elements.What is the result after bubble sort completes? int list[] = {2,56,34,25,73,46,89,10,5,16};

A) 89 73 56 46 34 25 16 10 5 2
B) 2 56 34 25 5 16 89 46 73
C) 2 5 10 16 25 34 46 56 73 89
D) 2 10 16 25 34 46 56 73 89

Question 22

Which of the following correctly states the quick sort algorithm?
A) if (the list size is greater than 1) {
A) Partition the list into four sublists.
B) Quick sort sublist1.
C) Quick sort sublist2.
D) Quick sort sublist3.
E) Quick sort sublist4.
D) Combine the sorted lists.
}
B) a. Find the location of the smallest element. b. Move the smallest element to the beginning of the
Unsorted list.
C) if (the list size is greater than 1) {
A) Partition the list into two sublists, say lowerSublist and
UpperSublist.
B) Quick sort lowerSublist.
C) Quick sort upperSublist.
D) Combine the sorted lowerSublist and sorted upperSublist.
}
D) if the list is of a size greater than 1 {

A) Divide the list into two sublists.
B) Merge sort the first sublist.
C) Merge sort the second sublist.
D) Merge the first sublist and the second sublist.
}

Question 23

With insertion sort,the variable firstOutOfOrder is initialized to ____,assuming n is the length of the list.

A) 0
B) 1
C) n - 1
D) n

Question 24

Let f and g be real-valued functions. Assume that f and g are nonnegative, that is, for all real numbers
and We say that is of g(n). written
if there exist positive constants c and such that For all

Question 25

When working with the unsorted portion of a list,the second step in a selection sort is to ____.

A) divide the list into two parts
B) move the smallest element to the top of the list (position 0)
C) move the smallest element to the beginning of the unsorted list
D) find the smallest element

Question 26

If n = 1000,to sort the list,bubble sort makes about ____ item assignments.

A) 10,000
B) 100,000
C) 250,000
D) 500,000

Question 27

In the bubble sort algorithm,the following code accomplishes swapping values in elements at positions index and index + 1.

A) list[index] = list[index + 1]
List[index + 1] = list[index]
B) list[index + 1] = list[index]
List[index] = list[index + 1]
C) list[index] = temp;
List[index] = list[index + 1];
Temp = list[index + 1];
D) temp = list[index];
List[index] = list[index + 1];
List[index + 1] = temp;

Question 28

For a list of length n,selection sort makes ____ item assignments.

A) n(n - 1)/2
B) 3(n - 1)
C) 3(n)
D) 4(n + 1)

Question 29

The ____________________ search algorithm is the optimal worst-case algorithm for solving search problems by using the comparison method.

Question 30

Let f be a function of n.By the term ____________________,we mean the study of the function f as n becomes larger and larger without bound.

Question 31

If a list of eight elements is sorted using selection sort,the unsorted list is ____ after the second iteration.

A) list[0] ... list[1]
B) list[0] ... list[6]
C) list[1] ... list[7]
D) list[2] ... list[7]

Question 32

The behavior of quick sort is ____ in the worst case and ____ in the average case.

A) O(nlog2n), O(nlog2n)
B) O(n2), O(n)
C) O(nlog2n), O(n2)
D) O(n2), O(nlog2n)

Question 33

____ sort requires knowing where the middle element of the list is.

A) Merge
B) Bubble
C) Insertion
D) Selection

Question 34

Assuming the following list declaration,which element is at the position 0 after the first iteration of selection sort? int list[] = {16,30,24,7,62,45,5,55}

A) 5
B) 7
C) 16
D) 62

Question 35

The behavior of merge sort is ____ in the worst case and ____ in the average case.

A) O(nlog2n), O(nlog2n)
B) O(n2), O(n)
C) O(nlog2n), O(n2)
D) O(n2), O(nlog2n)

Question 36

We can trace the execution of a comparison-based algorithm by using a graph called a ____.

A) pivot table
B) partition table
C) comparison tree
D) merge tree

Question 37

For a list of length n,insertion sort makes ____ key comparisons,in the worst case.

A) n(n - 1)/4
B) n(n - 1)/2
C) n2
D) n3

Question 38

In the case of an unsuccessful search,it can be shown that for a list of length n,a binary search makes approximately ____________________ key comparisons.

Question 39

When moving array values for insertion sort,to move list[4] into list[2],first ____.

A) move list[2] to list[3]
B) delete list[2]
C) move list[4] to list[3]
D) copy list[4] into temp

Question 40

To construct a search algorithm of the order less than log?n,it cannot be ____________________ based.

Question 41

For a list of length n,the bubble sort makes exactly ____________________ key comparisons.

Question 42

The quick sort algorithm uses the ____________________ technique to sort a list.

Question 43

The top node of a comparison tree is call the ____________________ node.

Question 44

In general,the selection sort algorithm is good only for small lists because ____________________ grows rapidly as n grows.

Question 45

In a quick sort,all of the sorting work is done by the function ____________________.

Question 46

The first step in the quick sort partition algorithm is to determine the ____________________ and swap it with the first element in the list.

Question 47

The following C++ function implements the ____________________ sort algorithm.
template
void Sort(elemType list[],int length)
{
for (int iteration = 1; iteration < length; iteration++)
{
for (int index = 0; index < length - iteration;
index++)
{
if (list[index] > list[index + 1])
{
elemType temp = list[index];
list[index] = list[index + 1];
list[index + 1] = temp;
}
}
}
}

Question 48

Any sorting algorithm that sorts a list of n distinct elements by comparison of the keys only,in its worst case,makes at least ____________________ key comparisons.

Question 49

A sequence of branches in a comparison tree is called a(n)____________________.

Question 50

A comparison tree is a(n)____________________ tree.