Arrays and strings in Python
Practice this questionWANT TO UNDERSTAND THE CONCEPT FIRST?Learn Arrays and strings in Python
Problems to practice
- Two Sum
- Best Time to Buy and Sell Stock
- Move Zeroes
- Product of Array Except Self
- Valid Palindrome
- Longest Substring Without Repeating Characters
- Group Anagrams
Example: two sum
def two_sum(nums, target):
seen = {}
for i, num in enumerate(nums):
needed = target - num
if needed in seen:
return [seen[needed], i]
seen[num] = i
return []Time and space complexity
- Time: O(n)
- Space: O(n)
Adapted from 18_DSA_PYTHON.md · “2. Arrays and strings in Python”. Code examples are study fragments. Difficulty and core labels are editorial estimates; version-specific behavior should be checked against your project.