Unit 4 #1

A student wrote the following procedure to calculate the sum of the integers from 1 to 5.

The student later decides to modify the procedure to calculate the sum of the integers from 1 to max, which represents any positive integer greater than 1.

Which of the following changes should be made to the procedure to meet the student’s goal?

1. -The procedure should take max as an input parameter.

2. -The condition in the REPEAT UNTIL block should be changed to count > max.

3. -The condition in the REPEAT UNTIL block should be changed to max < 5.

Responses

• I only

• 
  II only

• 
  I and II

• 
  I and III

In the following procedure, assume that the parameter x is an integer.

Which of the following best describes the behavior of the procedure?

• It displays nothing if x is negative and displays true otherwise.

• 
  It displays nothing if x is negative and displays false otherwise.

• It displays true if x is negative and displays nothing otherwise.

• It displays true if x is negative and displays false otherwise.

In the procedure Mystery below, the parameter number is a positive integer.

Which of the following best describes the result of running the procedure Mystery?

• The procedure returns true when the initial value of number is 2, and it otherwise returns false.

• The procedure returns true when the initial value of number is greater than 2, and it otherwise returns false.

• 
  The procedure returns true when the initial value of number is even, and it otherwise returns false.

• The procedure returns true when the initial value of number is odd, and it otherwise returns false.

In the following procedure, the parameters x and y are integers.

Which of the following is the most appropriate documentation to appear with the calculate procedure?

• Displays the value of x + (y / x).The value of the parameter x must not be 0.

• Displays the value of x + (y / x).The value of the parameter y must not be 0.

• Displays the value of (x + y) / x.The value of the parameter x must not be 0.

• Displays the value of (x + y) / x.The sum of the parameters x and y must not be 0.

In the following procedure, the parameter age represents a person’s age. The procedure is intended to return the name of the age group associated with age. People who are under 18 are considered minors, people who are 65 and older are considered senior citizens, and all other people are considered adults. The procedure does not work as intended.

Line 1:  PROCEDURE ageGroup(age)

Line 2:  {

Line 3:     result ← "adult"

Line 4:     IF(age ≥ 65)

Line 5:     {

Line 6:        result ← "senior citizen"

Line 7:     }

Line 8:     RETURN(result)

Line 9:

Line 10:    result ← "adult"

Line 11:    IF(age < 18)

Line 12:    {

Line 13:       result ← "minor"

Line 14:    }

Line 15:    RETURN(result)

Line 16: }

Removing which two lines of code will cause the procedure to work as intended?

Select two answers.

• Line 3

• 
  Line 8

• Line 10

• 
  Line 15

In the following procedure, the parameter numList is a list of numbers and the parameters j and k are integers.

PROCEDURE swapListElements(numList, j, k)

{

newList ← numList

newList[j] ← numList[k]

newList[k] ← numList[j]

RETURN(newList)

}

Which of the following is the most appropriate documentation to appear with the swapListElements procedure?

• Returns a copy of numList with the elements at indices j and k interchanged.The value of j must be between 0 and the value of k, inclusive.

• Returns a copy of numList with the elements at indices j and k interchanged.The values of j and k must both be between 1 and LENGTH(numList), inclusive.

• 
  Interchanges the values of the parameters j and k.The value of j must be between 0 and the value of k, inclusive.

• 
  Interchanges the values of the parameters j and k.The values of j and k must both be between 1 and LENGTH(numList), inclusive.

In the following procedure, the parameter max is a positive integer.

PROCEDURE printNums(max)

{

count ← 1

REPEAT UNTIL(count > max)

{

DISPLAY(count)

count ← count + 2

}

}

Which of the following is the most appropriate documentation to appear with the printNums procedure?

• Prints all positive even integers that are less than or equal to max.

• Prints all positive odd integers that are less than or equal to max.

• Prints all positive even integers that are greater than max.

• Prints all positive odd integers that are greater than max.

The question below uses a robot in a grid of squares. The robot is represented as a triangle, which is initially in the bottom-left square of the grid and facing toward the top of the grid.

 

Code for the procedure Mystery is shown below. Assume that the parameter p has been assigned a positive integer value (e.g., 1, 2, 3, …).

Which of the following shows a possible result of calling the procedure?

• 
• 
• 
• 

n the following procedure, the parameter str is a string and the parameter num is a number.

PROCEDURE printArgs(str, num)

{

DISPLAY(num)

DISPLAY(str)

DISPLAY(num)

}

Consider the following code segment.

printArgs("**", 1)

printArgs("*", 2)

What is displayed as a result of executing the code segment?

• 
• 
• 
• 

In the following procedure, the parameter n is an integer greater than 2.

Which of the following best describes the value returned by the procedure?

• The procedure returns nothing because it will not terminate.

• The procedure returns the value of 2 * n.

• The procedure returns the value of n * n.

• The procedure returns the sum of the integers from 1 to n.