Algorithm and Developing Programs

Daniel and Derek are pair programming partners in an introductory computer science course. While creating their Guess My Number game in which the computer tries to guess a number that the human player is thinking of between 1 and 100, Derek pointed out that the reason

their program wasn’t working as expected was because the program generated its next guess before checking with the player to see if the computer generated guess was correct. This is an example of a problem with the use of which programming construct?

• Selection

• Sequencing

• Iteration

• Recursion

A particular algorithm that sorts a list of numbers takes longer to run for long lists than it does for short lists. As the length of the list grows, the amount of time increases exponentially. Which of these could describe the algorithm’s performance? (pick two)

• Linear

• Constant

• Square

• Cube

Consider a robot which can move forward, turn left, turn right, and look ahead within the provided grid. Robots must not share a space with pedestrians, marked with P’s here. Pedestrians move around the grid at random. At a minimum, a robot must use which of the following programming constructs to safely navigate to its charging station, marked C?

• Sequencing and Iteration

• Iteration and Selection

• Sequencing and Selection

• Sequencing, Selection, and Iteration

Consider a robot which within the provided grid, can move forward, turn, and check to see if there’s a wall or charging station in front of it. Consider the proposed algorithm to get the robot to its charging station, marked C.

Step 1: Move Forward

Step 2: If Charging Station Ahead

Step 2a: Move Forward

Step 2b: Turn Right

Step 3: If Wall Ahead

Step 3a: Stop

Step 4: Repeat From Step 1

Which two of the steps in the proposed algorithm must be swapped for the robot to successfully find its charging station without running into the wall?

• 1

• 2b

• 3a

• 4

While running for president, Barack Obama was interviewed by Google’s chairman Eric Schmidt. Schmidt asked Obama, “What is the most efficient way to sort a million 32-bit integers?” Obama’s response was, “I think the bubble sort would be the wrong way to go.” Which of these sorts would be a better choice?

• Binary Sort

• Insertion Sort

• Quick Sort

• Selection Sort

After discussing strategies for searching an unordered list, your class broke up into groups to create posters to explain the linear search algorithm. One group made a flowchart. Another group listed the steps in pseudocode. Some posters also showed blocks-based code in Scratch or text-based code in JavaScript. The teacher determined that all posters correctly represented the linear search algorithm. Which of the posters list solutions that could be executed on a computer as written? (pick two)

• Flowchart

• Scratch

• Pseudocode

• Javascript

Algorithms can be expressed in a number of languages, including

I. Text-based languages

II. Blocks-based languages

III. Natural languages such as English

IV. Flowcharts

V. Pseudocode

• I and II only

• I, II, and IV only

• IV and V only

• I, II, III, IV, and V

A client requested a software developer to create an app to determine whether a submitted photo was taken in a national park and whether the photo was of a bird. Which of the tasks would be the most computationally intensive?

• uploading the photo

• checking the device's location when the photo was taken

• determining whether the photo is of a bird

• determining whether the location is in a known national park

Credit card companies process many thousands of transactions every minute, some of which are made by criminals using stolen cards or card numbers. It is impossible to know exactly whether or not a transaction is fraudulent, but companies try to reduce the amount of money lost by using solutions to inspect each transaction, determining whether it should be allowed or denied. Which kind of problem-solving technique is used in this case?

• heuristic

• optimization

• search

• minimization

Some problems can be solved precisely in a reasonable amount of time, while others necessitate approximation to find a solution quickly. Which of the following problems would be challenging for a computer to find an exact solution in a reasonable amount of time? Choose two.

• Generating a high school’s master schedule based on teacher availability and student course requests that gets as many students into the classes they requested as possible

• Calculating the amount of money each mobile phone subscriber owes for the previous month’s service for one of the country’s top three mobile carriers

• Determining the least expensive round-trip airfare for a particular trip given the departure date, the destination, the return date, and the return city.

• Finding the current grade point average for every high school student in a district of more than 9,000 students K-12.