MCQs about Time and Space Complexity Of a Program

Why is 6th one d??

6th one is d because the outer loop is running n times and inner nested loop is running m times so O(nm)
Think of it like this inner loop is running m times for each i so m+m+m+…(n times) which is m
n or as written n*m

1 B
2 C
3 B
4 B
5 C
6 D
7 C
8 C
9 C
10 B
11 A
12 C
13 C
14 B
15 B
16 B
17 B
18 D
19 B
20 B
21 C

How to do Q 13 and Q 14 ?? Anyone Please help me to understand

For Q13, the inner loop goes ‘m’ times and the outer loop run for ‘log2(n)’ times as on each iteration the I value decreases by 2(half).

For Q14, Both the loops have a factor increase and decrease in the times of iterations by 2. Instead of running from i to n in i-=1. It goes i, i/2, i/4, i/6,…1. Similarly, j goes j, j2, j4,…m.
Hence, log2(m) * log2(n)

From other comments, 20 should be option B.
Explanation, please?

1-B
2-C
3-B
4-B
5-C
6-D
7-C
8-C
9-C
10-B
11-A
12-C
13-C
14-B
15-B
16-B
17-B
18-D
19-B
20-D
21-D

  1. B
  2. C
  3. B
  4. B
  5. C
  6. D
  7. C
  8. C
  9. C
  10. B
  11. A
  12. C
  13. C
  14. B
  15. B
  16. B
  17. B
  18. D(guess)
  19. D(guess)
  20. B
  21. C

The harmonic series is a divergent series. log(n) is an approximation.

  1. b.
  2. c.
  3. b.
  4. b.
  5. c.
  6. d.
  7. c.
  8. c.
  9. c.
  10. b.
  11. a.
  12. c.
  13. c.
  14. b.
  15. b.
  16. b.
  17. b.
  18. d.
  19. b.
  20. d.
  21. d.

Yes, I was also of the same opinion.

Yes, You are wright.

Q1: B
Q2: C
Q3: B
Q4: B
Q5: C
Q6: D
Q7: C
Q8: C
Q9: C
Q10: B
Q11: A
Q12: C
Q13: C
Q14: B(I guess)
Q15: B
Q16: B
Q17: B
Q18: D
Q19: B
Q20: B
Q21: C

Q1: B
Q1: B
Q1: B
Q1: B
Q1: B
Q1: B

Hi, can you please explain Q4?

I am not sure if you could not understand the problem or you seek the solution. I will assume that you seek the solution.

Note that ans = log (1) + log (2) + \dots + log (n) = log (n!) = \Theta (nlog (n)). For last equality : look here

1.b
2.c
3.b
4.b
5.c
6.d
7.c
8.c
9.c
10.b
11.a
12.c
13.c
14.b
15.b
16.b
17.b
18.d
19.b
20.b
21.a

1 → B
2 → C
3 → B
4 → B
5 → C
6 → D
7 → C
8 → C
9 → C
10 → B
11 → A
12 → C
13 → C
14 → B
15 → B
16 → B
17 → B
18 → D
19 → B
20 → B
21 → A

1 B
2 C
3 B
4 B
5 C
6 D
7 C
8 C
9 C
10 B
11 A
12 C
13 B
14 A
15 C
16 B
17 B
18 D
19 B
20 B
21 D