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Grade 11 Algorithm Efficiency (Big-O) Worksheet with Answers

Grade 11 (US) · Year 12 (UK) · Class 11 (India) · Computer Science

Unit 3: AlgorithmsEfficiencyCSTA 3B-AP-11

Comparing how the number of steps grows: O(1), O(log n), O(n) and O(n²). This free high school worksheet has 12 questions and a full answer key. Print it or save it as a PDF — every answer is checked by code, not guessed.

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Algorithm Efficiency (Big-O)

Grade 11 · Computer Science

Score___ / 12

Name

Class

Date

Learning goal: Efficiency · CSTA 3B-AP-11

Directions: Read each question carefully and write your answer on the line. Use the diagram to help you.

RememberHow fast do steps grow?

nstepsO(1)O(log n)O(n)O(n²)One loop over n items → O(n)A loop inside a loop → O(n²)Halving each time → O(log n)Fixed number of steps → O(1)
  1. 1

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1for k in range(n):2print(k)
  2. 2

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1for x in range(8):2print(x)
  3. 3

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1for k in range(10):2print(k)
  4. 4

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1x = n2while x > 1:3x = x // 2
  5. 5

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1print(items[3])
  6. 6

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1for x in range(n):2for m in range(x):3print(x, m)
  7. 7

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1for k in range(n):2print(k)3for j in range(n):4print(j)
  8. 8

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1for i in range(n):2print(i)3for j in range(n):4print(j)
  9. 9

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1total = 02for x in range(n):3total = total + x
  10. 10

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1for k in range(0, n, 2):2print(k)
  11. 11

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1print(items[2])
  12. 12

    What is the time complexity of this code? Choose O(1), O(log n), O(n) or O(n²).

    1for k in range(n):2for y in range(20):3print(k, y)

★ Challenge corner for fast finishers

9 computers each connect directly to every other computer with one cable. How many cables are needed?

How did I do?

Teacher's comments

Free printable worksheets with answer keys · aethelsystems.com/worksheets/computer/11/big_o

Answer key (click to show)
  1. 1.O(n)
  2. 2.O(1)
  3. 3.O(1)
  4. 4.O(log n)
  5. 5.O(1)
  6. 6.O(n²)
  7. 7.O(n)
  8. 8.O(n)
  9. 9.O(n)
  10. 10.O(n)
  11. 11.O(1)
  12. 12.O(n)
  13. ★36 (challenge corner)

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