Question 1

Consider the problem of arranging matchsticks so as to form a row of squares, as shown below for three squares and ten matchsticks.

Accepted Answer

A) 4 * squares; 
B) 3 + matchsticks(squares - 1); 
C) 4 + matchsticks(squares - 1); 
D) matchsticks(squares + 4); 
A) 4 * squares; 
B) 3 + matchsticks(squares - 1); 
C) 4 + matchsticks(squares - 1); 
D) matchsticks(squares + 4);

Question 2

When a recursive method is called correctly, and it does not perform recursion, what must be true?

Accepted Answer

A) Both a terminating condition and a recursive case condition were true. 
B) A terminating condition was true. 
C) All recursive case conditions were true. 
D) One recursive case condition was true. 
A) Both a terminating condition and a recursive case condition were true. 
B) A terminating condition was true. 
C) All recursive case conditions were true. 
D) One recursive case condition was true.

Question 3

Complete the code for the calcPower recursive method shown below, which is intended to raise the base number passed into the method to the exponent power passed into the method:

Accepted Answer

A) answer = baseNum * calcPower (baseNum -1, exponent - 1); 
B) answer = baseNum * calcPower (baseNum, exponent); 
C) answer = baseNum * calcPower (baseNum -1, exponent); 
D) answer = baseNum * calcPower (baseNum, exponent - 1); 
A) answer = baseNum * calcPower (baseNum -1, exponent - 1); 
B) answer = baseNum * calcPower (baseNum, exponent); 
C) answer = baseNum * calcPower (baseNum -1, exponent); 
D) answer = baseNum * calcPower (baseNum, exponent - 1);

Question 4

Given the following code snippet:   What value will be returned when this code is executed with a call to newCalc(15)?

Accepted Answer

A) 2 
B) 6.5 
C) 2.5 
D) 6 
A) 2 
B) 6.5 
C) 2.5 
D) 6

Question 5

Consider the code for the recursive method riddle shown in this code snippet:   To avoid infinite recursion, which of the following lines of code should replace the current terminating case?

Accepted Answer

A) if (n = 0) 
D) The terminating case as shown will avoid infinite recursion. 
A) if (n = 0) 
D) The terminating case as shown will avoid infinite recursion.

Question 6

Given the following class code:   What values will be printed?

Accepted Answer

A) 1, 3, and 6 
B) 3, 6, 9, and 12 
C) 1, 3, 6, and 9 
D) 3, 6, and 9 
A) 1, 3, and 6 
B) 3, 6, 9, and 12 
C) 1, 3, 6, and 9 
D) 3, 6, and 9

Question 7

Consider the fib method from the textbook shown below.   Calling fib(3) will trigger ___ recursive call(s) and execute the terminating condition ___ time(s), respectively.

Accepted Answer

A) 1, 1 
B) 1, 2 
C) 2, 2 
D) 2, 1 
A) 1, 1 
B) 1, 2 
C) 2, 2 
D) 2, 1

Question 8

Complete the code for the calcPower recursive method shown below, which is intended to raise the base number passed into the method to the exponent power passed into the method:

Accepted Answer

A) if (exponent == -1) 
B) if (exponent == 1) 
C) if (exponent != 1) 
D) if (exponent == 0) 
A) if (exponent == -1) 
B) if (exponent == 1) 
C) if (exponent != 1) 
D) if (exponent == 0)

Question 9

Consider the square method shown below that takes a non-negative int argument.   What would a call to square(4) return?

Accepted Answer

A) 256 
B) 4 
C) 16 
D) 64 
A) 256 
B) 4 
C) 16 
D) 64

Question 10

Complete the following code snippet, which is intended to be a recursive method that reverses a String value:

Accepted Answer

A) return reverseIt(s.substring(0)) + s.charAt(1); 
B) return reverseIt(s.substring(1)) + s.charAt(1); 
C) return reverseIt(s.substring(0)) + s.charAt(0); 
D) return reverseIt(s.substring(1)) + s.charAt(0); 
A) return reverseIt(s.substring(0)) + s.charAt(1); 
B) return reverseIt(s.substring(1)) + s.charAt(1); 
C) return reverseIt(s.substring(0)) + s.charAt(0); 
D) return reverseIt(s.substring(1)) + s.charAt(0);

Question 11

A recursive method without a special terminating case would _________

Accepted Answer

A) be more efficient. 
B) never terminate. 
C) end immediately. 
D) not be recursive. 
A) be more efficient. 
B) never terminate. 
C) end immediately. 
D) not be recursive.

Question 12

Consider the following recursive code snippet:   }
Identify the terminating condition(s) of method mystery?

Accepted Answer

A) n  0 
C) n == 1 
D) n <= 0 or n == 1 
A) n  0 
C) n == 1 
D) n <= 0 or n == 1

Question 13

Consider the recursive method myPrint:   What is printed for the call myPrint(8)?

Accepted Answer

A) 4 
B) 21 
C) 10 
D) 8 
A) 4 
B) 21 
C) 10 
D) 8

Question 14

Consider the permutations method from the textbook, which is intended to return all permutations of the word passed in as a parameter.Which line contains the terminating condition in the permutations recursive method?

Accepted Answer

A) line #1 
B) line #9 
C) line #6 
D) line #8 
A) line #1 
B) line #9 
C) line #6 
D) line #8

Question 15

Which statement(s) about recursion are true?
i.Recursion is faster than iteration.
II.Recursion is often easier to understand than iteration.
III.Recursive design has an economy of thought.

Accepted Answer

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

Question 16

Consider the problem of displaying a pattern of asterisks that form a triangle of height h, as shown below for h = 4:

Accepted Answer

A) shape(0, height - 1); 
B) shape( 0, height - 1 ); 
C) shape(1, height); 
D) shape(0, height); 
A) shape(0, height - 1); 
B) shape( 0, height - 1 ); 
C) shape(1, height); 
D) shape(0, height);

Question 17

Consider the permutations method from the textbook, which is intended to return all permutations of the word passed in as a parameter.What special cases for the simplest values are used by the permutations method to terminate the recursion?

Accepted Answer

A) It terminates the recursion when it encounters a string with one character. 
B) It terminates the recursion when it encounters a string with two characters. 
C) It terminates the recursion when it encounters the empty string or a string with one character. 
D) It terminates the recursion when it encounters the empty string. 
A) It terminates the recursion when it encounters a string with one character. 
B) It terminates the recursion when it encounters a string with two characters. 
C) It terminates the recursion when it encounters the empty string or a string with one character. 
D) It terminates the recursion when it encounters the empty string.

Question 18

Complete the code for the myFactorial recursive method shown below, which is intended to compute the factorial of the value passed to the method:

Accepted Answer

A) return (anInteger * (myFactorial(anInteger - 1))); 
B) return (anInteger * (myFactorial(anInteger))); 
C) return ((anInteger - 1) * (myFactorial(anInteger))); 
D) return ((anInteger - 1)*(myFactorial(anInteger - 1))); 
A) return (anInteger * (myFactorial(anInteger - 1))); 
B) return (anInteger * (myFactorial(anInteger))); 
C) return ((anInteger - 1) * (myFactorial(anInteger))); 
D) return ((anInteger - 1)*(myFactorial(anInteger - 1)));

Question 19

Recursion will take place if any of the following happen:
i.method A calls method B, which calls method C
II.method A calls method B, which calls method A
III.method A calls method A

Accepted Answer

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

Question 20

Consider the following recursive code snippet:

Accepted Answer

A) 1 
B) 11 
C) 5 
D) 6 
A) 1 
B) 11 
C) 5 
D) 6

Exam 13: Recursion

Consider the problem of arranging matchsticks so as to form a row of squares, as shown below for three squares and ten matchsticks.

When a recursive method is called correctly, and it does not perform recursion, what must be true?

Complete the code for the calcPower recursive method shown below, which is intended to raise the base number passed into the method to the exponent power passed into the method:

Given the following code snippet: What value will be returned when this code is executed with a call to newCalc(15)?

Consider the code for the recursive method riddle shown in this code snippet: To avoid infinite recursion, which of the following lines of code should replace the current terminating case?

Given the following class code: What values will be printed?

Consider the fib method from the textbook shown below. Calling fib(3) will trigger ___ recursive call(s) and execute the terminating condition ___ time(s), respectively.

Complete the code for the calcPower recursive method shown below, which is intended to raise the base number passed into the method to the exponent power passed into the method:

Consider the square method shown below that takes a non-negative int argument. What would a call to square(4) return?

Complete the following code snippet, which is intended to be a recursive method that reverses a String value:

A recursive method without a special terminating case would _________

Consider the following recursive code snippet: } Identify the terminating condition(s) of method mystery?

Consider the recursive method myPrint: What is printed for the call myPrint(8)?

Consider the permutations method from the textbook, which is intended to return all permutations of the word passed in as a parameter.Which line contains the terminating condition in the permutations recursive method?

Which statement(s) about recursion are true? i.Recursion is faster than iteration. II.Recursion is often easier to understand than iteration. III.Recursive design has an economy of thought.

Consider the problem of displaying a pattern of asterisks that form a triangle of height h, as shown below for h = 4:

Consider the permutations method from the textbook, which is intended to return all permutations of the word passed in as a parameter.What special cases for the simplest values are used by the permutations method to terminate the recursion?

Complete the code for the myFactorial recursive method shown below, which is intended to compute the factorial of the value passed to the method:

Recursion will take place if any of the following happen: i.method A calls method B, which calls method C II.method A calls method B, which calls method A III.method A calls method A

Consider the following recursive code snippet:

Introduction

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Fundamental Data Types

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Consider the fib method from the textbook shown below. Calling fib(3) will trigger _ recursive call(s) and execute the terminating condition _ time(s), respectively.