Mixed practice set 2

Practice set

Q1MCQ1 markOutput

What does this print?

#include <stdio.h>
int main(void)
{
    int a[3][4] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}};
    printf("%d %d %d\n", *(*(a + 1) + 2), *(a[2] + 1), **a + 5);
    return 0;
}

• (A) 7 10 6
• (B) 7 10 2
• (C) 3 10 6
• (D) 6 9 6

Q2MCQ2 marksStrings

What does this print?

#include <stdio.h>
#include <string.h>
int main(void)
{
    char s[] = "GATE2027";
    char *p = s + 4;
    printf("%d %d %s %c\n", (int)sizeof(s), (int)strlen(p), p + 1, *s + 1);
    return 0;
}

• (A) 8 4 027 H
• (B) 9 4 2027 G
• (C) 9 4 027 H
• (D) 9 5 027 H

Q3MCQ1 markRecursion

What does this print?

#include <stdio.h>
void p(int n)
{
    if (n == 0) return;
    printf("%d ", n);
    p(n - 1);
    printf("%d ", n);
}

int main(void)
{
    p(3);
    printf("\n");
    return 0;
}

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

Q4MCQ2 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"); }

struct node *g(struct node *h)
{
    struct node *p = NULL, *q = h;
    if (h == NULL || h->next == NULL) return h;
    while (q->next != NULL) {
        p = q;
        q = q->next;
    }
    p->next = NULL;
    q->next = h;
    return q;
}

int main(void)
{
    show(g(build(5)));
    return 0;
}

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

Q5NAT1 markSwitch

What does this print?

#include <stdio.h>
int main(void)
{
    int x = 2, s = 0;
    switch (x) {
        case 1: s += 1;
        case 2: s += 2;
        case 3: s += 3; break;
        default: s += 10;
    }
    printf("%d\n", s);
    return 0;
}

Numerical answer: ________

Q6MCQ2 marksCircular queue

What does this print?

#include <stdio.h>
#define N 5
int q[N], front = 0, rear = 0;                 /* front: slot before the first element */

int enq(int x) { if ((rear + 1) % N == front) return 0; rear = (rear + 1) % N; q[rear] = x; return 1; }
int deq(void) { front = (front + 1) % N; return q[front]; }

int main(void)
{
    int i, ok = 0;
    for (i = 1; i <= 6; i++) ok += enq(i);
    deq();
    deq();
    ok += enq(7);
    printf("%d %d %d\n", ok, front, rear);
    return 0;
}

• (A) 5 2 5
• (B) 5 2 0
• (C) 6 2 1
• (D) 4 2 4

Q7NAT1 markAddress

int A[10][20] is stored row-major at base 1000 with 4-byte int. Address of A[5][7]?

Numerical answer: ________

Q8NAT2 marksTraversals

Inorder D B E A F C G and postorder D E B F G C A. Write the preorder as letters; how many nodes come before C in it?

Numerical answer: ________

Q9MCQ1 markTrees

A binary tree has 20 leaves. How many nodes have exactly two children?

• (A) 21
• (B) 19
• (C) 20
• (D) 10

Q10MCQ2 marksAVL

Insert 50, 40, 30, 35, 33 into an empty AVL tree. The preorder at the end is:

• (A) 35 30 33 40 50
• (B) 40 33 30 35 50
• (C) 40 35 30 33 50
• (D) 40 30 35 33 50

Q11NAT1 markHeaps

How many distinct max-heaps can be built with 6 distinct keys?

Numerical answer: ________

Q12MCQ2 marksGraphs

Graph with edges A–B, A–C, B–D, C–D, D–E, E–F. Which is a valid DFS order from A?

• (A) A B D E C F
• (B) A B C D E F
• (C) A B D C E F
• (D) A C B D E F