Mixed practice set 1

Practice set

Q1MCQ1 markOutput

What does this print?

#include <stdio.h>
int main(void)
{
    int a = 0, b = 5, c;
    c = a++ && b++;
    printf("%d %d %d\n", a, b, c);
    c = a++ || b++;
    printf("%d %d %d\n", a, b, c);
    return 0;
}

• (A) 1 5 0 then 2 5 1
• (B) 1 5 0 then 2 6 1
• (C) 1 6 0 then 2 7 1
• (D) 0 5 0 then 1 5 1

Q2NAT1 markOutput

What does this print?

#include <stdio.h>
int f(void)
{
    static int s = 1;
    s = s * 2;
    return s;
}

int main(void)
{
    int i, t = 0;
    for (i = 0; i < 4; i++) t += f();
    printf("%d\n", t);
    return 0;
}

Numerical answer: ________

Q3MCQ2 marksOutput

What does this print?

#include <stdio.h>
int main(void)
{
    int a[] = {10, 20, 30, 40, 50};
    int *p = a + 1, *q = &a[4];
    printf("%d %d %d\n", *p + 2, *(p + 2), (int)(q - p));
    return 0;
}

• (A) 12 40 3
• (B) 22 40 12
• (C) 22 30 3
• (D) 22 40 3

Q4NAT2 marksRecursion

What is the second number printed?

#include <stdio.h>
int calls = 0;

int f(int n)
{
    calls++;
    if (n <= 1) return 1;
    return f(n - 1) + f(n - 2);
}

int main(void)
{
    int r = f(5);
    printf("%d %d\n", r, calls);
    return 0;
}

Numerical answer: ________

Q5MCQ1 markMacros

What does this print?

#include <stdio.h>
#define SQ(x) x * x

int main(void)
{
    printf("%d %d\n", SQ(2 + 3), 100 / SQ(5));
    return 0;
}

• (A) 11 4
• (B) 25 4
• (C) 25 100
• (D) 11 100

Q6MCQ2 marksLinked list

What does this print?

#include <stdio.h>
#include <stdlib.h>
struct node {
    int data;
    struct node *next;
};

struct node *build(int n)            /* list 1 -> 2 -> ... -> n */
{
    struct node *h = NULL, *p;
    while (n > 0) {
        p = malloc(sizeof(struct node));
        p->data = n--;
        p->next = h;
        h = p;
    }
    return h;
}

void show(struct node *h) { for (; h != NULL; h = h->next) printf("%d ", h->data); printf("\n"); }

void f(struct node *h)
{
    if (h == NULL) return;
    if (h->next != NULL) f(h->next->next);
    printf("%d ", h->data);
}

int main(void)
{
    f(build(5));
    printf("\n");
    return 0;
}

• (A) 5 4 3 2 1
• (B) 4 2
• (C) 5 3 1
• (D) 1 3 5

Q7MCQ1 markPostfix

The postfix form of a + b * (c − d) / e is:

• (A) a b c d - e / * +
• (B) a b c - d * e / +
• (C) a b c d - * e / +
• (D) a b + c d - * e /

Q8MSQ2 marksStack permutations

Input 1 2 3 4 5 is pushed in order (pops allowed any time). Which output sequences are possible?

• (A) 5 1 2 3 4
• (B) 4 5 3 1 2
• (C) 2 4 3 1 5
• (D) 3 2 5 4 1

Q9NAT1 markBST

A BST has preorder 15 10 8 12 20 17 25. How many leaves does it have?

Numerical answer: ________

Q10NAT2 marksHeap

Keys 3, 1, 6, 5, 2, 4 are inserted one by one into an empty max-heap. What key is at 0-based index 2 at the end?

Numerical answer: ________

Q11MCQ1 markGraphs

Maximum edges in a simple undirected graph with 7 vertices:

• (A) 21
• (B) 14
• (C) 49
• (D) 42

Q12MCQ2 marksBig-O

for (i = n; i > 0; i /= 2) for (j = 0; j < i; j++) count++; runs count++ how many times, in Θ terms?

• (A) Θ(log n)
• (B) Θ(n)
• (C) Θ(n log n)
• (D) Θ(n²)