Mastering the 'Find First Occurrence' Problem with Rolling Hash in Strings | Leetcode #28 Explained

"Mastering the 'Find First Occurrence' Problem with Rolling Hash in Strings | Leetcode #28 Explained"

Summary: This video covers an in-depth solution to Leetcode's Problem #28, "Find the Index of the First Occurrence in a String." Learn how to implement a rolling hash technique for substring searching to find the first occurrence of a "needle" string within a "haystack." We’ll explore examples, edge cases, and hashing intricacies to handle collisions, ensuring efficient substring matching even for large inputs.

Key Highlight:

Discover the rolling hash method to optimize substring search.
Learn to handle hash collisions accurately for precise substring matching.
Walkthrough of practical examples and edge cases to strengthen your understanding.
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Problem Summary:
Objective: Compress a string by using the count of repeated characters. The original array should be modified in-place with the new length of the string.
Input: An array of characters.
Output: The new length of the array after compression.
Key Approach to Solve the Problem:
Initialize Pointers and Counter:

Use two pointers: one (read) to iterate over the array and another (write) to update the array with compressed characters.
Initialize a counter to track the frequency of each character.
Iterate and Count Characters:

As you iterate, count the occurrences of each character.
When a different character is encountered or the end of the array is reached, proceed to compression.
Compress and Update:

Write the character and its count (if greater than 1) to the write pointer's position.
Update the write pointer accordingly.
Handle Single Characters:

If a character occurs only once, just write the character without the count.
Return New Length:

The write pointer's final position indicates the new length of the compressed string.
This problem requires careful manipulation of pointers and in-place array modifications to ensure space efficiency. The challenge lies in correctly handling the compression logic and updating the array without additional space for the compressed version.

[HustlerCoder]

"Mastering the 'Find First Occurrence' Problem with Rolling Hash in Strings | Leetcode #28 Explained"

Summary: This video covers an in-depth solution to Leetcode's Problem #28, "Find the Index of the First Occurrence in a String." Learn how to implement a rolling hash technique for substring searching to find the first occurrence of a "needle" string within a "haystack." We’ll explore examples, edge cases, and hashing intricacies to handle collisions, ensuring efficient substring matching even for large inputs.

Key Highlight:

Discover the rolling hash method to optimize substring search.
Learn to handle hash collisions accurately for precise substring matching.
Walkthrough of practical examples and edge cases to strengthen your understanding.

[HustlerCoder]

Disclaimer : This content is not at all related with my current organizational work. Also, it has no any commercial value of any form.

[HustlerCoder]

This question, I initially picked but later realized that it is just required to implement on method from string class so not very meaningful. Please ignore the string method, please try to implement by own, Using Rolling Hash, which I will do update very soon.