C949- Data Structures and Algorithms I, C949 WGU Exam 2023

Which statement describes a queue data structure? - Answer- It is a sequence of elements in which insertions can take place only at the back end and deletions can take place only at the front end. What are the official indexes for the list list01 given this declaration? int[ ] list01 = {0, 2, 4, 6, 8, 10}; - Answer- 0, 1, 2, 3, 4, 5 Which abstract data type (ADT) has elements of the same type so that the elements can be retrieved based on the index or position? - Answer- List Which category of data does ("FB", 75.00, 75.03, 74.90) represent in the pseudocode? import datetime def middle(stock, date): symbol, current, high, low = stock return (((high + low) / 2), date) mid_value, date = middle(("FB", 75.00, 75.03, 74.90), (2014, 10, 31)) - Answer- Tuple Which data type does the mystery function return? return_type mystery (int R) { int NumUnits = R;return NumUnits * 3.14; } - Answer- Double Which value is appropriate for the variable middle given the pseudocode? function mystery() { string last; string first; char middle; int phone; float rate; } - Answer- 'D' What is the most efficient data type to use for this data set of a fixed size in Java? a = [0, 0, 1, 4, 7, 16, 31, 64, 127] - Answer- Array What is true about garbage collection? - Answer- It reclaims memory from data structures implemented using linked allocations. What is true about a data structure implemented using linked allocation? - Answer- Storage is allocated using pointers to new locations as needed. What are the array elements corresponding to the mid-values in the first and second iterations of a binary search in an array arr = {45, 77, 89, 90, 94, 99, 100} and key = 100? - Answer- 90 and 99 What is the effect on the object Computing regarding garbage collection? Computing obj = new Computing(); obj = null; - Answer- It is automatically available for garbage collection. What are the mid-values in the first and second levels of recursion in this binary search? int arr = {46, 76, 89, 90, 94, 99, 100} and key = 99 - Answer- 90 and 99 Which data set is represented using the dictionary data type? - Answer- A set of students and their test scores What is a characteristic of keys in an associative dictionary data type? - Answer- They are unique and immutable. Which method can be used to take a value out of a dictionary? - Answer- D1[key].remove(value) Given this data dictionary in Python: dict = {'white':0x0000, 'black':0x1111} Which command/function generates the output ['white','black']? - Answer- () Items were added sequentially in this stack starting with 'ham': 'sausage' 'toast' 'eggs' 'ham' What is the correct order of contents after the push operation is performed with the value 'bacon'? - Answer- 'bacon' 'sausage' 'toast' 'eggs' 'ham' Items were added sequentially in this stack starting with "dog": "bird" "rabbit" "cat" "dog" What is the return value of the pop operation? - Answer- "bird" Which sequence of letters represents preorder traversal of the nodes of this tree? A / B C / / D E / F G H / I - Answer- A B C D F E G I H An array soc of size 1009 is used where the index is an integer in [0,1008] and the hash-function key%1009. Where will the data associated with the key given by the last 4 social security digits '2023' be stored? - Answer- In soc[5] A stack s, a queue q, and a max value priority queue p each have a single 3 in them. Next (4), (4), and (4) are executed. What is the triple ((), (), ())? - Answer- (4,3,4) This stack reads left to right with the top to the right: 'green' 'yellow' 'blue' 'red' What could be the stack after a push operation? - Answer- ['red','blue','yellow', 'green', 'purple"] Items were added sequentially onto the stack starting with 'red': 'green' 'yellow' 'blue' 'red' What is the stack after a pop operation? - Answer- 'yellow' 'blue' 'red' Which command helps to speed up comparisons using dictionary keys during a dictionary (d) lookup in this pseudocode clip? h = hash(key) for pair in d: if h == pair[0]: return pair[1] - Answer- hash(object) What does the method any(b) return in Python if b is a dictionary? - Answer- Returns True if any key of the dictionary is true. Which Java method is used to read bytes from a standard file? - Answer- J.FileInputStream Which command will retrieve an item from the top of the stack? - Answer- Pop() Which command will insert object x at position index in a list? - Answer- Add(int index, Object x) Which command will return true if x is in a list, otherwise return false? - Answer- Contains(Object x) When should a dictionary be used instead of a list? - Answer- When the program uses key-value pairs as its data Which data structure is indexed? - Answer- Array Which data structure may only store homogeneous data elements? - Answer- Arrays Which data structure uses a last in, first out (LIFO) removal of items? - Answer- Stack Given: heapList = [22, 33, 44, 55, 66] Which index is the right child of item 22? - Answer- 44 What is the logical first step in an algorithm that extracts all the positive values from a given list of numbers? - Answer- Initialize the result to an empty list What is displayed when n = 2 in this pseudocode? for(int i = 2; i <= n; i++){ for(j = 0; j <= n;){ display j; j = j + n/2; the division is integer division, decimal part neglected } } - Answer- 0, 1, 2 Given a set of numeric data and two declared variables: small and max, what is the logical first step in an algorithm that finds the smallest number? - Answer- Checking that the list contains at least one number What is the output of the pseudocode below if the variables declared in the main program are global? Main Declare X as Integer, Y as Integer Set X = 1 Set Y = 2 Call Sub(X, Y) Write X Write Y End Program Subprogram Sub(Integer Num1, Integer Num2 as Reference) Declare X as Integer Set Num1 = 3 Set Num2 = 4 Set X = 5 Write X End Subprogram - Answer- 5 14 How many times in this pseudocode is the function F called? Main Declare K as Integer K = 3 Set Result = F(K) Write Result End Program Function F(N) as Integer If N == 1 Then Set F = 1 Else Set F = N * F(N - 1) Set N = N - 1 End If End Function - Answer- 3 What is displayed in Step 5 if A = 15 and B = 5 in the pseudocode below? Step 1: Start Step 2: Read A, B Step 3: C= A*B Step 4: D=A/B Step5: Print C Step 6: Stop - Answer- 75 What is displayed in step 3 if midterm = 60 and final = 65 in this pseudocode? Step 1: Declare midterm, final as integer Step 2: average = (midterm+final)/2 Step 3: if (average < 50) then Print "Fail" Else Print "Pass" endif - Answer- Pass How many times will count++ execute when i = 3, in this pseudocode? int count = 0; int N = 4;