CSE220 Spring 2025 Midterm Practice

Exam Information

• Course: CSE 220, Fall 2024

• Instructors: Carl Alphonce, Ethan Blanton, Eric Mikida

• Student Name: Rifa Tasfia

• UBIT Name: rifatasf

• Variant: k

• Seat Number: Cll

• Total Points: 43

Academic Integrity

• Policy Agreement:

  • Signing indicates agreement to abide by academic integrity policies, ensuring the exam is the student’s independent work.

Instructions

• Write name on the front of every page.

• Verify accuracy of name and UBITname on the cover sheet.

• Notify an instructor or TA of errors immediately.

• Answer each question to the best of your ability.

• Use margins for notes or calculations.

• Correct mis-marked answers by drawing a line through the wrong answer and circling the correct one.

• Check all questions are answered before submission.

Questions Overview

True/False (7 points)

• Question 1: The length of a C array is stored by the compiler.

  • Answer: False

• Question 2: Every array of characters is a C string.

  • Answer: False

• Question 3: A single line of C code corresponds to a single machine instruction.

  • Answer: False

• Question 4: x && y and x == y are always the same if x and y are integers.

  • Answer: False

• Question 5: The representations of numbers used by computers violate some properties of normal arithmetic.

  • Answer: True

• Question 6: Every memory access is for an 8-byte word.

  • Answer: True

• Question 7: Padding in a C struct is permitted only in between members.

  • Answer: False

Multiple Choice (24 points)

• Question 8: What expression has value 100 given 'a' = 97?

  • Answer: 'd'

• Question 9: Which expressions result in "yes" being printed?

  • Answer: testA(4,3) && testB()

• Question 10: Number of bits the processor can read/write in memory access depends on:

  • Answer: Size of registers on the processor and memory bus width

• Question 11: Which expressions are always true, assuming a, b, c are double?

  • Answer: a * a >= 0 and (x + y) + z = x + (y + z)

• Question 12: For the given code, which have value 53?

  • Answer: value, *ptr

• Question 13: Relationship between arrays and pointers in C:

  • Answer: They are different, but closely related, with shared syntax.

• Question 14: Address space relative to laptop RAM:

  • Answer: Address space is larger than the size of the laptop's RAM and the address space of a single process is equivalent to the RAM installed in 4,294,967,296 such laptops.

• Question 15: Legal expressions in C99 for given struct example:

  • Answer: r = s, &r == &s

• Question 16: Which have a stride of 1 on x86-64?

  • Answer: char, int*

• Question 17: Size of the given structure:

  • Answer: 16 bytes

• Question 18: Relationship of struct sizes:

  • Answer: sizeof(struct A) must be greater than sizeof(struct B)

• Question 19: Which address is guaranteed to be invalid?

  • Answer: 0x0000000000000000

Short Answer (12 points)

• Question 20: Variable declaration for assignment legality:

  • Answer: char *x;

• Question 21: Insertion of padding into structures ensures:

  • Answer: Alignment

• Question 22: Memory allocation segments:

  • (a) string: Data

  • (b) f: text

  • (c) iSize: BSS

  • (d) p: stack

  • (e) *p: Heap

• Question 23: Find out requested memory size from malloc:

  • Answer: You can't.