Software Engineering Midterm 2
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Quiz to prepare for CS373 Midterm 2
- 1.Define the function arraycopy(), iteratively, such that it mimics Java's System.arraycopy(). a = [2, 3, 4] b = [2, 3, 4] arraycopy(a, 0, b, 1, 2) assert b == [2, 2, 3] a = [2, 3, 4] arraycopy(a, 0, a, 1, 2) assert a == [2, 2, 3] a = [2, 3, 4] b = [2, 3, 4] arraycopy(a, 1, b, 0, 2) assert b == [3, 4, 4] a = [2, 3, 4] arraycopy(a, 1, a, 0, 2) assert a == [3, 4, 4]
- 2.#!/usr/bin/env python #What does the following code do? import sys in = sys.stdin.readline() a = in[:-1] p = a[::-1] print a==p
- A.
Checks to see if a and p point to the same memory address.
- B.
Doesn't compile.
- C.
Checks if input is a palindrome (reversed string is the same string).
- D.
Stores the first character in a. Stores the first character from that and stores it in p. Checks to see if their contents are equal.
- E.
Prints true
- F.
Prints false
- G.
Stores the first character in input into a. Stores last character in a into p. Compares
- 3.""" the set constructor REQUIRES: Select all that apply """
- A.
Only lists, not tuples or frozen sets
- B.
Only tuples, not lists or frozen sets
- C.
Only lists and tuples, not frozen sets
- D.
Any iterable container
- E.
An iterable container with hashable objects
- F.
Mutable objects
- G.
Hashable objects
- H.
Anything
- 4.""" Given any two sets s1 and s2, Select all that apply: """
- A.
S1|s2 == (s1^s2) | (s1&s2)
- B.
S1^s2 == (s2|s1)-(s1&s2)
- C.
S1-s1 == s1^s1
- D.
S1-s1 == s2^s2
- E.
S1&s2
- F.
S1
- G.
S1&s2
- H.
S1|s2
- I.
S1&s2 = (s1|s2) - (s1^s2)
- 5.""" What is the output of the following program? """ #!/usr/bin/env python x = [1, 2, 3] y = [4, 5, 6, 7] print [v + w for v in x if v % 2 for w in y if w % 3]
- A.
[8]
- B.
[5,6,8,7,8,10]
- C.
[5,7,9,7]
- D.
[1,3,4,5,7]]
- E.
[2,6]
- F.
[5,7,6,8,8,10]
- 6.""" What is the output of this program? Or does it cause an error? """ #!/usr/bin/env python a = '\ \ \ abc\ \ \ ' print len(a)
- 7.""" After the following code, which of the following are valid? Select all that apply. """ a = [1]
- A.
A.append()
- B.
A.append(1)
- C.
A[0]=3
- D.
A.append([1,2,3])
- E.
A.extend(1)
- F.
A.extend([1,2,3])
- G.
A.append([])
- 8.""" Which of the following are iterable? """
- A.
Range(0,5)
- B.
Range(5)
- C.
List([0,1,2,3,4])
- D.
Set([0,1,2,3,4])
- E.
Dict({1:a})
- F.
"abcde"
- G.
Set([0,1,2,3,4])
- H.
01234
- 9.Which of the following are hashable? Select all that apply.
- A.
Set([1,2,3])
- B.
Tuple(1,2,3)
- C.
List([1,2,3])
- D.
Frozenset([1,2,3])
- E.
"abc123"
- F.
12345
- G.
A() (where A is a valid class)
- 10.Which of the following can make a copy of a frozenset f f = frozenset([1,"abc",3.45])
- A.
C = set() c = f.copy
- B.
C = set() c |= f
- C.
C = set(f)
- 11.What is the output of the following program? [x, y] = z = 2, 3 print x, y, z
- 12.""" What is the output to the following program? """ def f (x, y, *z) : return [x, y, z] def g (x, y, **z) : return [x, y, z] t = (2, 3, 4) print f(*t) d = {"u" : 4, "y" : 3, "x" : 2} print g(**d) d = {"u" : 4, "y" : 3, "v" : 5} print g(2, **d)
- 13.""" What is the output of the following program? """ s=abCbA print s[4:-6:-2]
- 14."""What is the output of the following program?""" x = set((1, 2, 3, 5)) y = set([1, 2, 4, 6]) z = (x & y) - (x ^ y) t = (y ^ x) - (y & x) print z print t
- 15.Which properties of this container are true? (These containers are equivalent) (language Container) c++ vector java ArrayList python list/tuple haskell array let b = beginning m = middle e = end
- A.
Inserting at b and m are O(n)
- B.
Deleting from b or m are O(n)
- C.
Adding to e is O(n)
- D.
Adding to e is ~O(1)
- E.
Adding to e is O(1)
- F.
Indexing is O(n)
- G.
Indexing is O(1)
- H.
Inserting at b or m are amortized constant
- I.
Inserting at b or m are ~O(1)
- 16.Which properties of this container are true? (These containers are equivalent) (language Container) c++ deque java Deque python deque haskell n/a let b = beginning m = middle e = end
- A.
Adding to b and e are O(1)
- B.
Adding to b and e are ~O(1)
- C.
Adding to b and e are O(n)
- D.
Deleting from b and e are O(1)
- E.
Deleting from b and e are ~O(1)
- F.
Deleting from b and e are O(n)
- G.
Indexing is O(1)
- H.
Indexing is O(n)
- 17.Which properties of this container are true? (These containers are equivalent) (language Container) c++ list java LinkedList python n/a haskell list/tuple Note: assume you already have a pointer to the location you want to insert or remove
- A.
Inserting is O(1)
- B.
Inserting is ~O(1)
- C.
Inserting is O(n)
- D.
Deleting is O(1)
- E.
Deleting is ~O(1)
- F.
Deleting is O(n)
- G.
Indexing is O(1)
- H.
Indexing is ~O(1)
- I.
Indexing is O(log n)
- J.
Indexing is O(n)
- 18.""" What does the following code output? """ a = [[0,0]]*2 a[0][0] = 1 print a
- A.
[[0,0], [0,0]]
- B.
Doesn't compile or throws an error
- C.
[[1,0], [1,0]]
- D.
[[1,1], [1,1]]
- E.
[[1,0], [0,0]]
- 19.Suppose l is a list. What does it mean to say if l:
- A.
If the first element is true
- B.
If all elements are true
- C.
If the list is empty
- D.
If the list is not empty
- 20.""" What is the output to the output of the following code? If more than one error is present, select all that apply """ L = [None]*10 L[0] = 123 L[1] = "abc" L[2] = 2.75 L[3:] = dict({"k":"v"}) print L
- A.
{'k': 'v'}
- B.
Error: can't initialize list with None variables
- C.
[123, 'abc', 2.75, 'k']
- D.
Error: list must be homogeneous (all objects same time)
- E.
Error: can't slice list (L[3:])
- F.
Error: assignment of slice must be of same length
- G.
Error: assignment of slice must be utterable
- H.
[123, 'abc', 2.75, 'v']
- I.
[123, 'abc', 2.75, {'k':'v'}]
- J.
123
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