Practice Problems
Reinforce Your Learning
Practice these string problems to strengthen your understanding of string manipulation concepts.
Difficulty Levels:
Reverse String
EasyWrite a function that reverses a string. The input string is given as an array of characters.
Example:
Input: ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]
Constraints:
- Do this in-place with O(1) extra memory.
Valid Anagram
EasyGiven two strings s and t, return true if t is an anagram of s, and false otherwise.
Example:
Input: s = "anagram", t = "nagaram"
Output: true
Constraints:
- The strings contain only lowercase English letters.
Longest Palindromic Substring
MediumGiven a string s, return the longest palindromic substring in s.
Example:
Input: s = "babad"
Output: "bab" or "aba" (both are valid)
Learning Objective
Reinforce your understanding of string manipulation concepts through practice problems.
Practice Makes Perfect
The best way to master string manipulation is through consistent practice. Below are problems of varying difficulty to help you build your skills.
Filter by Difficulty:
| Problem | Difficulty | Concepts | Status |
|---|---|---|---|
Reverse String | Easy | Two Pointers, In-place | Not Started |
Valid Anagram | Easy | Hash Table, Counting | Not Started |
Longest Palindromic Substring | Medium | Dynamic Programming, Expansion | Not Started |
String to Integer (atoi) | Medium | String Parsing, Edge Cases | Not Started |
Regular Expression Matching | Hard | Dynamic Programming, Recursion | Not Started |
Problem of the Day
Reverse Words in a String
MediumGiven an input string, reverse the order of the words.
Input: "the sky is blue"
Output: "blue is sky the"
Your Progress
Complete your first problem to start tracking progress
Next Steps
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