Multiple Choice

Multiple Choice Section 1.1 Specification and Design

1. Why is writing easily modifiable code important?
   • A. Easily modifiable code generally has a quicker run time.
   • B. Most real world programs require change at some time.
   • C. Most text editors make it easy to modify code.
   • D. Several people may be writing the same function at the same time.

2. Which phase of the software life-cycle is usually the most expensive?
   • A. Analysis and specification of the task
   • B. Design
   • C. Implementation
   • D. Maintenance and evolution

3. What will happen if a function is executed and the precondition for the function is not met?
   • A. An error message will be printed.
   • B. The program will loop indefinitely.
   • C. The system will crash.
   • D. Any of the above results could happen.

4. Answer true or false for this statement: When programming in teams, the specification of a function should be written by the person writing the code for the function.
   • TRUE.
   • FALSE.

5. Answer true or false for this statement: When programming individually (not in a team), there is no need to write a specification for a function
   • TRUE.
   • FALSE.

6. If the precondition fails, it is a good idea to write a useful error message and then halt the program. Why is the program halted?
   • A. Most operating systems forbid continuation.
   • B. The function is no longer guaranteed to make the postcondition true.
   • C. The function's memory requires have become exponential (or worse).
   • D. The function's running time has become exponential (or worse).

7. Which of these is used to stop the program execution when a precondition is not met.
   • A. assert();
   • B. exit();
   • C. return();
   • D. void();

8. Which of these statements will always cause a program to halt? (x is an int variable).
   • A. assert(10 > 0);
   • B. assert(10 < 0);
   • C. assert(x < 0);
   • D. None of the above will always cause a program to halt.

   Multiple Choice Section 1.2 Running Time Analysis

9. What does a run-time analysis usually count?
   • A. The number of arithmetic and other operations required for the program to run
   • B. The number of megabytes required for the program to run
   • C. The number of seconds required for the program to run
   • D. The number of seconds plus the number of megabytes
   • E. The number of seconds times the number of megabytes

10. Which of these is the correct big-O expression for 1+2+3+...+n?
    • A. O(log n)
    • B. O(n)
    • C. O(n log n)
    • D. O(n)

11. Which of the following formulas in big-O notation best represent the expression n+35n+6?
    • A. O(n)
    • B. O(n)
    • C. O(n)
    • D. O(42)

12. Answer true or false for this statement: For all possible inputs, a linear algorithm to solve a problem must perform faster than a quadratic algorithm to solve the same problem.
    • TRUE.
    • FALSE.

13. Answer true or false for this statement: True or false: An algorithm with worst case time behavior of 3n takes at least 30 operations for every input of size n=10.
    • TRUE.
    • FALSE.

14. What term is used to describe an O(n) algorithm.
    • A. Constant
    • B. Linear
    • C. Logarithmic
    • D. Quadratic

15. Here is some code for an integer variable n:

     while (n > 0) { n = n/10; // Use integer division } 

    What is the worst-case time analysis for the above loop?
    • A. O(1)
    • B. O(log n)
    • C. O(n)
    • D. O(n)

16. Express the formula (n - 2)*(n - 4) using big-O notation:
    • A. O(1)
    • B. O(8)
    • C. O(log n)
    • D. O(n)
    • E. None of the above

    Multiple Choice Section 1.3 Testing and Debugging

17. Why is it important to test boundary values when testing programs?
    • A. Calculating by hand, it's easy to find the right answers for boundary values.
    • B. Debuggers are easier to use when testing boundary values.
    • C. In practice, a large proportion of errors arise from boundary values.
    • D. The correct execution of a function on all boundary values proves a function is correct.

18. How may boundary values for a function be found?
    • A. Pick values that are one step away from different behavior.
    • B. Pick values that make the precondition equal to the postcondition.
    • C. Pick values where the precondition is false.
    • D. Pick values where the postcondition is false.

19. Which software tool will best help you determine whether your test cases are fully exercising your code?
    • A. Compiler
    • B. Debugger
    • C. Make
    • D. Pine
    • E. Profiler