Question 1

Which sort algorithm is used in the sort method in the Java Arrays class when the array length is less than 7?

Accepted Answer

A)  merge sort 
B)  quicksort 
C)  selection sort 
D)  insertion sort 
A)  merge sort 
B)  quicksort 
C)  selection sort 
D)  insertion sort

Question 2

Assume we are using quicksort to sort an array in ascending order. What can we conclude about the indexes of two pivot elements placed in consecutive recursive calls?

Accepted Answer

A)  They are randomly located. 
B)  They are in different halves of the array. 
C)  They are both in the same half of the array. 
D)  They are adjacent. 
A)  They are randomly located. 
B)  They are in different halves of the array. 
C)  They are both in the same half of the array. 
D)  They are adjacent.

Question 3

A portion of your program implements a loop in which each step contains a fixed number of actions. What can you conclude about the running time of this section of code?

Accepted Answer

A)  Its running time will be O(n). 
B)  Its running time will be O(n2). 
C)  Its running time will be O(log (n)). 
D)  Its running time will be O(n log (n)). 
A)  Its running time will be O(n). 
B)  Its running time will be O(n2). 
C)  Its running time will be O(log (n)). 
D)  Its running time will be O(n log (n)).

Question 4

Which function has a faster growth rate: θ(n1/2) or θ(log(n))?

Accepted Answer

A)  θ(log(n)) 
B)  θ(n1/2) 
C)  They are the same. 
D)  They can't be compared. 
A)  θ(log(n)) 
B)  θ(n1/2) 
C)  They are the same. 
D)  They can't be compared.

Question 5

Merge sort has a O(n log2(n)) complexity. If a computer can sort 1,024 elements in an amount of time x, approximately how much longer will it take the computer to sort 1,024 times that many, or 1,048,576 elements?

Accepted Answer

A)  1,024 times longer 
B)  2,048 times longer 
C)  8,192 times longer 
D)  1,048,576 times longer 
A)  1,024 times longer 
B)  2,048 times longer 
C)  8,192 times longer 
D)  1,048,576 times longer

Question 6

The code segment below displays a pattern of asterisks. Select an expression to complete the code segment so that the resulting algorithm has O(n) running time. for (int k = 0; k < n; k++)
{
For _______________________
{
System.out.print("*");
}
System.out.println();
}

Accepted Answer

A) (int j = n; j > 0; j = j / 2) B) (int j = n; j > 0; j--) C) (int j = 1; j < k; j++) D) (int j = 1; j <= 10; j++) A) (int j = n; j > 0; j = j / 2) B) (int j = n; j > 0; j--) C) (int j = 1; j < k; j++) D) (int j = 1; j <= 10; j++)

Question 7

Consider the following code snippet: public static void sort(int[]A) insertion sort

Accepted Answer

A)  {
For (int i = 1; i  0 && a[j - 1] > next)
{
A[j] = a[j - 1];
J--;
}
A[j] = next;
}
}
What sort algorithm is used in this code? 
B)  selection sort 
C)  merge sort 
D)  quicksort 
A)  {
For (int i = 1; i  0 && a[j - 1] > next)
{
A[j] = a[j - 1];
J--;
}
A[j] = next;
}
}
What sort algorithm is used in this code? 
B)  selection sort 
C)  merge sort 
D)  quicksort

Question 8

If the Arrays static method binarySearch is called on an array of 10 elements and returns a value of 10, what can be concluded?
I the element is not found
II that value cannot be returned from method binarySearch
III if added, the element would be the largest element in the array

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  I and III 
A)  I 
B)  II 
C)  III 
D)  I and III

Question 9

The sort method of the Arrays class sorts arrays containing objects of classes that implement the ____ interface.

Accepted Answer

A)  Sortable 
B)  Ordered 
C)  Array 
D)  Comparable 
A)  Sortable 
B)  Ordered 
C)  Array 
D)  Comparable

Question 10

In the worst case, a linear search locates a value in an array of length n in ____ steps.

Accepted Answer

A)  O(n2) 
B)  O(log n) 
C)  O(n) 
D)  O(log n2) 
A)  O(n2) 
B)  O(log n) 
C)  O(n) 
D)  O(log n2)

Question 11

After 9 iterations of selection sort working on an array of 10 elements, what must hold true?

Accepted Answer

A)  The largest element is correctly placed by default. 
B)  One more iteration is needed to complete the sort. 
C)  The smallest element is incorrectly placed. 
D)  The largest element is incorrectly placed. 
A)  The largest element is correctly placed by default. 
B)  One more iteration is needed to complete the sort. 
C)  The smallest element is incorrectly placed. 
D)  The largest element is incorrectly placed.

Question 12

The analysis for the number of visits in a binary search begins with the equation, T(n) = T(n / 2) + 1. What does the number 1 represent in this equation?

Accepted Answer

A)  One element visit before a recursive call on one half of the array. 
B)  The total number of recursions required. 
C)  The fact that the number of elements is odd. 
D)  The fact that we search either the left half or the right half, but not both. 
A)  One element visit before a recursive call on one half of the array. 
B)  The total number of recursions required. 
C)  The fact that the number of elements is odd. 
D)  The fact that we search either the left half or the right half, but not both.

Question 13

Suppose you have a phone number and need to find the address that it corresponds to. If there are 2,000,000 entries, how many do you expect to search in a printed phone directory before finding the address you are looking for?

Accepted Answer

A)  Approximately 50,000 records. 
B)  Approximately 75,000 records. 
C)  Approximately 1,000,000 records. 
D)  Approximately 1,200,000 records. 
A)  Approximately 50,000 records. 
B)  Approximately 75,000 records. 
C)  Approximately 1,000,000 records. 
D)  Approximately 1,200,000 records.

Question 14

Given an ordered array with 15 elements, how many elements must be visited in the worst case of binary search?

Accepted Answer

A)  8 
B)  4 
C)  3 
D)  2 
A)  8 
B)  4 
C)  3 
D)  2

Question 15

Given an ordered array with 31 elements, how many elements must be visited in the worst case of binary search?

Accepted Answer

A)  16 
B)  8 
C)  5 
D)  4 
A)  16 
B)  8 
C)  5 
D)  4

Question 16

A portion of your program includes the loop shown in the code snippet below to examine the elements of an array arr:
Int count = 0;
Int targetVal = 70;
For (int i = 0; i = targetVal)
{
Count++;
}
}
What can you conclude about the running time of this section of code?

Accepted Answer

A)  Its running time will be O(n). 
B)  Its running time will be O(n2). 
C)  Its running time will be O(log (n)). 
D)  Its running time will be O(n log (n)). 
A)  Its running time will be O(n). 
B)  Its running time will be O(n2). 
C)  Its running time will be O(log (n)). 
D)  Its running time will be O(n log (n)).

Question 17

Which sort algorithm starts with an initial sequence of size 1, which is assumed to be sorted, and increases the size of the sorted sequence in the array in each iteration?

Accepted Answer

A)  insertion sort 
B)  selection sort 
C)  merge sort 
D)  quicksort 
A)  insertion sort 
B)  selection sort 
C)  merge sort 
D)  quicksort

Question 18

If a call to the Arrays static method binarySearch returns a value of -10, what can be concluded?
I the element is not in the array
II the element is at index 10
III the element can be inserted at index 9

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  I and III 
A)  I 
B)  II 
C)  III 
D)  I and III

Question 19

The method findLargest examines the elements of an array arr which contains non-negative values public static int findLargest(int[] arr)
{
Int curLargest = -1;
For (int i = 0; i = curLargest)
{
CurLargest = arr[i];
}
}
Return curLargest;
}
What can you conclude about the running time of this section of code?

Accepted Answer

A)  Its running time will be O(n). 
B)  Its running time will be O(n2). 
C)  Its running time will be O(log (n)). 
D)  Its running time will be O(n log (n)). 
A)  Its running time will be O(n). 
B)  Its running time will be O(n2). 
C)  Its running time will be O(log (n)). 
D)  Its running time will be O(n log (n)).

Question 20

A search technique where, in each step, you split the size of the search in half is called a____ search.

Accepted Answer

A)  random 
B)  binary 
C)  linear 
D)  merging 
A)  random 
B)  binary 
C)  linear 
D)  merging

Exam 14: Sorting and Searching

Which sort algorithm is used in the sort method in the Java Arrays class when the array length is less than 7?

Assume we are using quicksort to sort an array in ascending order. What can we conclude about the indexes of two pivot elements placed in consecutive recursive calls?

A portion of your program implements a loop in which each step contains a fixed number of actions. What can you conclude about the running time of this section of code?

Which function has a faster growth rate: θ(n1/2) or θ(log(n))?

Merge sort has a O(n log2(n)) complexity. If a computer can sort 1,024 elements in an amount of time x, approximately how much longer will it take the computer to sort 1,024 times that many, or 1,048,576 elements?

The code segment below displays a pattern of asterisks. Select an expression to complete the code segment so that the resulting algorithm has O(n) running time. for (int k = 0; k < n; k++) { For _______________________ { System.out.print("*"); } System.out.println(); }

Consider the following code snippet: public static void sort(int[]A) insertion sort

If the Arrays static method binarySearch is called on an array of 10 elements and returns a value of 10, what can be concluded? I the element is not found II that value cannot be returned from method binarySearch III if added, the element would be the largest element in the array

The sort method of the Arrays class sorts arrays containing objects of classes that implement the ____ interface.

In the worst case, a linear search locates a value in an array of length n in ____ steps.

After 9 iterations of selection sort working on an array of 10 elements, what must hold true?

The analysis for the number of visits in a binary search begins with the equation, T(n) = T(n / 2) + 1. What does the number 1 represent in this equation?

Suppose you have a phone number and need to find the address that it corresponds to. If there are 2,000,000 entries, how many do you expect to search in a printed phone directory before finding the address you are looking for?

Given an ordered array with 15 elements, how many elements must be visited in the worst case of binary search?

Given an ordered array with 31 elements, how many elements must be visited in the worst case of binary search?

Which sort algorithm starts with an initial sequence of size 1, which is assumed to be sorted, and increases the size of the sorted sequence in the array in each iteration?

If a call to the Arrays static method binarySearch returns a value of -10, what can be concluded? I the element is not in the array II the element is at index 10 III the element can be inserted at index 9

A search technique where, in each step, you split the size of the search in half is called a____ search.

Introduction

Using Objects

Implementing Classes

Fundamental Data Types

Decisions

Loops

Arrays and Array Lists

Designing Classes

Inheritance

Interfaces

Inputoutput and Exception Handling

Object-Oriented Design

Recursion

The Java Collections Framework

Basic Data Structures

Tree Structures

Generic Classes

Graphical User Interfaces

Streams and Binary Inputoutput

Multithreading

Internet Networking

Relational Databases

XML

Web Applications

Filters

Which function has a faster growth rate: θ(n^1/2) or θ(log(n))?

Merge sort has a O(n log₂(n)) complexity. If a computer can sort 1,024 elements in an amount of time x, approximately how much longer will it take the computer to sort 1,024 times that many, or 1,048,576 elements?