Recall & Review
beginner
What is the main idea behind the naive string pattern matching algorithm?
The naive algorithm checks for the pattern at every possible position in the text by comparing characters one by one until a match is found or all positions are checked.
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beginner
In the naive string pattern matching algorithm, what happens when a mismatch occurs during comparison?
When a mismatch occurs, the algorithm shifts the pattern by one position to the right in the text and starts comparing again from the first character of the pattern.
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intermediate
What is the worst-case time complexity of the naive string pattern matching algorithm?
The worst-case time complexity is O(m * n), where m is the length of the pattern and n is the length of the text, because it may check every character of the text for every character of the pattern.
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beginner
Show the output of the naive string pattern matching algorithm when searching for pattern "abc" in text "abcabcabc".
The pattern "abc" is found at positions 0, 3, and 6 in the text.
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intermediate
Why is the naive string pattern matching algorithm not efficient for large texts and patterns?
Because it checks every possible position in the text and compares characters one by one without skipping, leading to many repeated comparisons especially when the pattern and text have repeated characters.
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What does the naive string pattern matching algorithm do when it finds a mismatch?
✗ Incorrect
The naive algorithm shifts the pattern by one position to the right and starts comparing again from the first character.
What is the time complexity of the naive string pattern matching algorithm in the worst case?
✗ Incorrect
The worst-case time complexity is O(m * n), where m is pattern length and n is text length.
If the pattern length is 3 and text length is 10, how many maximum comparisons can the naive algorithm make?
✗ Incorrect
Maximum comparisons = (text length - pattern length + 1) * pattern length = (10 - 3 + 1) * 3 = 8 * 3 = 24.
Which of these is a key disadvantage of the naive string pattern matching algorithm?
✗ Incorrect
The naive algorithm can be slow because it checks every position without skipping.
What is the first step in the naive string pattern matching algorithm?
✗ Incorrect
The algorithm starts by comparing the pattern with the text from position 0.
Explain how the naive string pattern matching algorithm works step-by-step.
Think about sliding the pattern over the text and checking each character.
You got /5 concepts.
Describe the time complexity of the naive string pattern matching algorithm and why it can be inefficient.
Consider how many times characters are compared in the worst case.
You got /4 concepts.