Homework Help is Here – Start Your Trial Now!
Engineering
Computer Science
def longest_unique_substring(s: str) -> str: Given a string , return the longest unique substring that occurs within . A unique substring is a substring within which DOES NOT have any repeating characters. As an example, "xd" is unique but "xxd" is not. If there are two equal length unique substrings within , return the one that starts first (i.e., begins at a smaller index). Note on grading for this question:

def longest_unique_substring(s: str) -> str: Given a string , return the longest unique substring that occurs within . A unique substring is a substring within which DOES NOT have any repeating characters. As an example, "xd" is unique but "xxd" is not. If there are two equal length unique substrings within , return the one that starts first (i.e., begins at a smaller index). Note on grading for this question:

Database System Concepts
Database System Concepts
7th Edition
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Chapter1: Introduction
Section: Chapter Questions
Problem 1PE
See similar textbooks
icon
Related questions
Question

- Do not add any imports, the ones that you need will be given to you.
- Do not use recursion.
- Do not use break/continue.
- Do not use try-except statements, you should be able to anticipate
or prevent any errors from happening at all!

def longest_unique_substring(s: str) -> str: Given a string <s>, return the longest unique substring that occurs within <s>. A unique substring is a substring within <s> which DOES NOT have any repeating characters. As an example, "xd" is unique but "xxd" is not. If there are two equal ength unique substrings within <s>, return the one that starts first (i.e., begins at a smaller index). Note on grading for this question: You've already implemented a function that can generate all the substrings of a given string in lab 5. You can use that logic to help here, but it will be quite slow. For this question, PERFORMANCE WILL MATTER, and we will run long tests with up to 10,000,000 characters as an input. To get full credit, an input of 10,000,000 characters should return the correct answer within 60 seconds (the instructor solution takes about 2). Helpful tips: In order to get your function to run fast, consider using a dictionary to store the indexes of previously seen characters, from there, you can follow a set of rules based on each new character you see to determine the length of the longest unique substring seen so far. >>> Longest_unique_substring ('aab') 'ab' pass
Transcribed Image Text:def longest_unique_substring(s: str) -> str: Given a string <s>, return the longest unique substring that occurs within <s>. A unique substring is a substring within <s> which DOES NOT have any repeating characters. As an example, "xd" is unique but "xxd" is not. If there are two equal ength unique substrings within <s>, return the one that starts first (i.e., begins at a smaller index). Note on grading for this question: You've already implemented a function that can generate all the substrings of a given string in lab 5. You can use that logic to help here, but it will be quite slow. For this question, PERFORMANCE WILL MATTER, and we will run long tests with up to 10,000,000 characters as an input. To get full credit, an input of 10,000,000 characters should return the correct answer within 60 seconds (the instructor solution takes about 2). Helpful tips: In order to get your function to run fast, consider using a dictionary to store the indexes of previously seen characters, from there, you can follow a set of rules based on each new character you see to determine the length of the longest unique substring seen so far. >>> Longest_unique_substring ('aab') 'ab' pass
Expert Solution
steps

Step by step

Solved in 2 steps with 1 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Problems on Dynamic Programming
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Database System Concepts
Database System Concepts
Computer Science
ISBN:
9780078022159
Author:
Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:
McGraw-Hill Education
Starting Out with Python (4th Edition)
Starting Out with Python (4th Edition)
Computer Science
ISBN:
9780134444321
Author:
Tony Gaddis
Publisher:
PEARSON
Digital Fundamentals (11th Edition)
Digital Fundamentals (11th Edition)
Computer Science
ISBN:
9780132737968
Author:
Thomas L. Floyd
Publisher:
PEARSON
C How to Program (8th Edition)
C How to Program (8th Edition)
Computer Science
ISBN:
9780133976892
Author:
Paul J. Deitel, Harvey Deitel
Publisher:
PEARSON
Database Systems: Design, Implementation, & Manag…
Database Systems: Design, Implementation, & Manag…
Computer Science
ISBN:
9781337627900
Author:
Carlos Coronel, Steven Morris
Publisher:
Cengage Learning
Programmable Logic Controllers
Programmable Logic Controllers
Computer Science
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education
SEE MORE TEXTBOOKS