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Module Quiz

Complete this quiz after finishing all concept and practice pages. Save your answers before opening separate quiz calibration. Treat it closed-book; check answers after finishing.

Current Module Questions​

Question 1: Hex Fluency​

How many bits fit in two hex digits? How many decimal values does a single byte span as unsigned?

Question 2: Two's Complement​

Give the 8-bit two's-complement representation of -1 and of -128, and explain why the second is "the negative without a positive."

Question 3: IEEE 754 Decoding​

Decode the 32-bit pattern 0x40490FDB as an IEEE 754 float.

Question 4: Undefined Behavior on Signed Overflow​

Predict the output. What does the C standard say?

int x = INT_MAX;
if (x + 1 < x) puts("overflowed");
else           puts("did not");

Question 5: Pointer Arithmetic Prediction​

Predict the output on a typical x86-64 system:

int a[5] = {10, 20, 30, 40, 50};
int *p = a + 2;
printf("%d %d %d\n", *p, p[-1], *(p + 2));

Question 6: Type-Scaled Arithmetic​

Given double *d; with d == 0x1000, what is the address value of d + 3? What about (char *)d + 3?

Question 7: Dangerous Cast​

Predict the bytes printed on a little-endian machine:

uint32_t x = 0xAABBCCDD;
unsigned char *p = (unsigned char *)&x;
printf("%02x %02x %02x %02x\n", p[0], p[1], p[2], p[3]);

Question 8: Segment Placement​

Where do each of these live (stack, heap, .data, .bss, .rodata)?

const char *msg = "hello";
int g_init = 5;
static int g_zero;
int main(void) {
    int local;
    int *p = malloc(4);
    return 0;
}

Question 9: Stack-Frame Tracing​

Briefly describe what the x86-64 function prologue push rbp; mov rbp, rsp; sub rsp, 32 does in words.

Question 10: Heap Discipline​

Is there a bug in this code, and if so, what kind?

char *p = malloc(32);
if (p != NULL) strcpy(p, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJ");
free(p);

Question 11: Use-After-Free​

Which line is the use-after-free?

char *s = malloc(16);
strcpy(s, "hello");
free(s);
printf("%s\n", s);

Question 12: Struct Layout Prediction​

On x86-64 with default alignment, what is sizeof(struct S)?

struct S { char c; int i; char d; };

Question 13: Endianness on the Wire​

On a little-endian host, uint32_t x = 0x01020304; write(fd, &x, 4);. Another machine reads the 4 bytes into its own uint32_t y with read. If that machine is big-endian, what does it see in y?

Question 14: Alignment vs Packing​

What is the risk of __attribute__((packed)) on a struct with an int field followed by a double field?

Question 15: Tricky Cast and Alignment Prediction​

Predict whether this compiles clean and what it prints on a typical Linux x86-64 system:

char buf[5] = { 0x78, 0x56, 0x34, 0x12, 0x00 };
uint32_t v;
memcpy(&v, buf, 4);
printf("0x%08x\n", v);

Interleaved Review Questions​

Prior Module Question 1 (S1 Module 3: Probability)​

What does linearity of expectation say, and why does it not require independence?

Prior Module Question 2 (S2 Module 1: Algorithm Analysis)​

Solve T(n) = 2 T(n/2) + n using the Master Theorem.

Prior Module Question 3 (S3 Module 2: Software Design)​

What is the core idea of the Single Responsibility Principle in one sentence?

Prior Module Question 4 (S4 Module 1: C Programming Fundamentals)​

What does static mean for a file-scope variable versus a function-scope variable in C?

Prior Module Question 5 (S1 Module 1: Proof Techniques)​

Prove by induction that sum_{i=1}^n i = n(n+1)/2.

Self-Assessment and Remediation​

Mastery Level (90-100% correct):

  • Retrieval is strong; complete all module and semester evidence gates before advancing.

Proficient Level (75-89% correct):

  • Review the missed concept pages and redo two problems of each missed type. Pay particular attention to pointer-arithmetic prediction and struct layout if those were the gaps.

Developing Level (60-74% correct):

  • Rework Practice 2 (pointers) and Practice 3 (memory errors / tools). Run at least three programs under ASan and at least one under Valgrind. The weakness is almost certainly under-using the tools.

Insufficient Level (<60% correct):

  • Return to Cluster 1 and Cluster 2 concept pages. Most likely issue: reading pointer code without drawing memory diagrams. Restart the concept sequence with a blank paper next to you and draw every pointer before asking "what is this code doing?"

All MP1–MP6 are required independently of quiz percentage.

Progression boundary​

Quiz performance calibrates retrieval and reasoning. It does not replace runnable work, changed-case transfer, the module assessment or required semester evidence. Consult practice calibration for the additional independent cases.