Python practice1

1. Problem: FizzBuzz Extended

Write a function fizz_buzz_extended(n) that returns a list of integers from 1 to n, but for multiples of 3, append "Fizz", for multiples of 5 append "Buzz", and for multiples of both 3 and 5 append "FizzBuzz":

2. Problem: Find the Longest Substring Without Repeating Characters

Write a function longest_substring(s) that returns the length of the longest substring of a given string s without repeating characters.

Problem: Flatten a Nested List

Write a function flatten(lst) that takes a nested list and returns a flattened version.

Problem: Valid Parentheses

Write a function is_valid_parentheses(s) that checks if a string containing only parentheses ()[]{} is valid.

Problem: Find Prime Numbers

Write a function find_primes(n) that returns a list of prime numbers up to n.

Problem: Group Anagrams

Write a function group_anagrams(words) that groups words that are anagrams of each other.

Problem: Merge Intervals

Write a function merge_intervals(intervals) that merges overlapping intervals.

Problem: Reverse Linked List

Given a singly linked list, write a function to reverse it.