Leetcode 5659. Minimum Length of String After Deleting Similar Ends | Summary and Q&A
TL;DR
The content explains an algorithm to minimize a specific string's length by removing matching prefixes and suffixes.
Key Insights
- 👻 The algorithm focuses on iterating through the string to look for matching characters at both ends, allowing for optimized character removal.
- ❤️🩹 A greedy approach is recommended, as it encourages the removal of as many characters as possible from both ends efficiently.
- ❓ Using two pointers facilitates a clear and logical method for tackling the string reduction problem without unnecessary complexity.
- ❓ The technique requires careful attention to ensure that not only do the prefix and suffix match, but they also consist of identical characters only.
- 👾 The algorithm does not employ any additional space, maintaining a constant space complexity, thus making it highly efficient for large strings.
- ❓ Understanding the problem's constraints is crucial for successfully applying the algorithm; only certain character combinations can be minimized.
- 🪈 The algorithm's effectiveness can be further enhanced by recognizing patterns in the string structure and the order of characters.
Transcript
hey there everyone welcome back to lead coding so this is the contest bi-weekly contest 45 and this is the problem number three of the contest so let us see what the problem statement is saying we are given a string consisting of a b and c and we have to apply the following algorithm so the first thing is we have to take a prefix consisting of simi... Read More
Questions & Answers
Q: What is the main goal of the algorithm described?
The goal of the algorithm is to reduce the length of a string composed of the characters 'a', 'b', and 'c' by repeatedly removing matching prefixes and suffixes. These are segments at the beginning and end of the string that consist of the same character, and the process continues until no more matching segments can be removed.
Q: How is the two-pointer technique applied in this algorithm?
The two-pointer technique involves maintaining pointers at the start and the end of the string. By comparing the characters at these pointers, the algorithm checks for matches. If the characters are identical, the algorithm increments the start pointer and decrements the end pointer, effectively removing the matching segments from consideration and allowing for potential further reductions.
Q: What happens when the characters at the start and end are not the same?
If the characters at the start and end of the string do not match, the algorithm terminates the removal process. At this point, the remaining substring length is calculated as the difference between the string length and the positions of the two pointers, leading to the minimum length that cannot be further reduced.
Q: What is the time complexity of the algorithm?
The time complexity of the proposed algorithm is O(n), where n is the length of the string. This efficiency arises from the linear traversal of the string through the two-pointer approach, ensuring that each character is considered only a limited number of times.
Summary & Key Takeaways
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The algorithm involves selecting matching prefixes and suffixes of identical characters from a given string and deleting them to reduce the string's size.
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The process includes using two pointers to identify matching characters at both ends of the string, which allows repetitive removals until no more matches are found.
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An example illustrates the method: by iteratively removing prefixes and suffixes until the string can be minimized, demonstrating a greedy approach for optimal performance.