CSE 1310 - Exams - Midterm 1 Practice Questions

Problem 1

Write a function factorial(number) that receives an integer as an argument and computes the factorial of the integer. The factorial of an integer is the product of all the positive integers less than or equal to that integer. For example, the factorial of 5 (denoted by 5!) is 5*4*3*2*1 = 120. The function should verify the input is a positive integer and return None if it is not.

Problem 2

Write a function keep_vowels(text) that takes a string as an argument and returns a new string that only keeps the vowels and spaces of the input string and omits the consonants. You can assume that the argument only contains letters and spaces, you do not need to write code to check for that. For example, keep_vowels('hello there') should return 'eo ee'.

Problem 3

Write a function capitalize_vowels(text) that satisfies the following specifications:

The function requires a string as an argument, and returns None if the argument is not a string.
The function returns a string that the same as the argument text, except that all vowels in text are capitalized. For example, capitalize_vowels('hello there') should return 'hEllO thErE'.

Problem 4

Write a function foo(S1) that takes as argument a string S1 that contains only letters and spaces, and returns a string S2 that contains first the consonants of S1 (in the order in which they appear in S1), and then the vowels of S1 (again, in the order in which they appear in S1). For example: foo('Hello world') should return the string 'Hllwrldeoo'.

Problem 5

We define that a string S is a well-formed name of a person if it follows the conventions:

S follows the form last_name + ", " + first name, where last_name and first_name are substrings.
last_name and first_name both start with a capital letter, and then only include lower-case letters
Between last_name and first_name, S contains only a comma and then a space character.
S should contain no additional characters beyond last_name, first_name, and the comma and space that separate last_name from first_name.

For example, "Smith, John" is a well-formed name. "Smith, John Edward" is NOT a well-formed name. "Smith-Johnson, Mary" is NOT a well-formed name. Write a function check_name that takes in as argument a string S and returns True if S is a well-formed name, and False otherwise. Don't handle the case where the argument S is not a string, but do handle correctly all cases where S is indeed a string.

Problem 6

Write a function multiple_options(N, option) that:

Returns None if N is not an integer or option is not an integer.
If option is equal to 1, the function returns the square of N.
If option is equal to 2, the function returns N multiplied by ten.
If option is equal to 3, the function returns N divided by three.
If the user enters any other number, the function returns 0.

Problem 7

Write a program that takes a string as an argument and returns a new string that only keeps the vowels and spaces of the input string and omits the consonants. You can assume that the argument only contains letters and spaces, you do not need to write code to check for that. For example, if you passed the function 'hello there', it would return 'eo ee'.

Problem 8

Write a function named compute_differences(n1, n2, n3) that:

Takes three arguments, n1, n2, n3, that are expected to be numbers (integers or floats).
If any argument is not a number (i.e., not an integer and not a float), the function should return None.
If arguments n1, n2, n3 are numbers, the function returns the largest value among these three values: n2 - n1, n3 - n2, and n3 - n1.

For example:

compute_differences(15, 2.5, 30) should return 27.5.
compute_differences(5, 10, 30) should return 25.

Problem 9

Write a function named foo(num) that:

Takes one argument, a number num.
If num is not an integer or float, it returns None.
If num is a number, it returns 3*num + 1.

For example:

foo(10) should return 31.
foo(2.5) should return 8.5.

Problem 10

Describe the execution of this program: what lines are executed; what namespaces come into existence and when; what variables are in each namespace and what are their values? Your answer must explicitly show the state of each namespace after every execution of a line.

def function1(z):       # line 1
    values = [1, 2, 3]  # line 2
    return values[z]    # line 3
                        # line 4
def function2(z, y):    # line 5
    if y < 0:           # line 6
        val = 0         # line 7
    elif y == 10:       # line 8
        val = 1         # line 9
    else:               # line 10
        val = 2         # line 11
    x = function1(val)  # line 12
    return x*z          # line 13
                        # line 14
x = 10                  # line 15
y = 2                   # line 16
print(function2(y, x))   # line 17

Problem 11

Write a function named repeat_number(s) that:

Takes one argument, an integer num.
Returns a number that repeats the digits of num 3 times.
If the argument is not an integer, the function should return None.

For example:

For input argument "hello!", it should return None, because the input argument is a string.
For input argument "23", it should return None, because the input argument is a string. .
For input argument 12.34, it should return None, because the input argument is a float. .
For input argument 1, it should return 111.
For input argument 241, it should return 241241241.
For input argument 322, it should return 322322322.

IMPORTANT: make sure that, when the input argument is an integer, the output is also an integer. In other words, make sure that, if the input argument is of type int, the return value is also of type int.

Problem 12

What does this function do? What does it return if x = 5?

def Func(x):
    total = 0
    for i in range(1, x+1):
        total += i * (i-1)
        
    return total

Your answer should be understandable by someone who does not know programming.

Problem 13

def counter(num, limit):          #line 1
    num += 1                      #line 2
    for x in range(1, num):       #line 3 
        print(x, end = ','),      #line 4
    print('\n')                   #line 5
    if (num ==  limit):           #line 6
        return                    #line 7
    else:                         #line 8
        counter(num, limit)       #line 9
                                  #line 10
num = 1                           #line 11
limit = 5                         #line 12
counter(num, limit)               #line 13

Problem 14

The Fibonacci sequence is 1,1,2,3,5,8, 13, ... You can see that the first and second numbers are both 1. Thereafter, each number is the sum of the previous two numbers. Write a function Fibonacci(N) that takes as input an integer N and prints the first N numbers of Fibonacci sequence.

For example, Fibonacci(15) prints the following:

1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610