There are many levels of Leetcode skills, ranging from being able to solve an Easy problem after much struggle (call this Level 1) to completely understanding all of the patterns and being able to solve any question within 10 minutes (Level 10). Depending on the internships you’re aiming for and how much free time you have, you should try to be somewhere between Level 4 and Level 8.

In this range, you’re able to recognize the patterns involved in Easy and Medium problems and reason through them fairly quickly. You probably won’t solve many Hard problems, but that’s ok. Feel free to aim for Levels 9 or 10, but we think that’s a waste of your time. You’re probably better suited spending that time on a personal project, perfecting your resume, or sending out networking emails.

Use the below problems to check your Level. If it takes you longer than 20 minutes to solve a problem, you haven’t quite achieved that Level yet. Also, it’s cheating to look up the solution and then do the problem immediately after. If you can’t solve a problem, find the solution online and make sure you understand it. Then, wait a few days for the knowledge to settle before you retest yourself. All of these problems have been covered by Neetcode on YouTube, so if you’re struggling, watch his videos!

Level Checkpoints

• Level 1: Single Number and Valid Palindrome 
• Level 2: Binary Search and Best Time to Buy and Sell Stock 
• Level 3: Pascal’s Triangle and Reverse Linked List 
• Level 4: Binary Tree Level Order Traversal and Set Matrix Zeroes 
• Level 5: 3Sum and House Robber 
• Level 6: Jump Game and Number of Islands
• Level 7: Coin Change  and Container with Most Water
• Level 8: Longest Increasing Subsequence and Clone Graph 
• Level 9: Trapping Rain Water and Word Search 
• Level 10: Merge k Sorted Lists and Word Search II