Title Acceptance Level Reverse Linked List 62.5% Easy Merge Two Sorted Lists 53.5% Easy Best Time to Buy and Sell Stock 50.5% Easy Climbing Stairs 47.8% Easy Symmetric Tree 46.8% Easy Maximum Subarray 46.5% Easy Two Sum 45.6% Easy Intersection of Two Linked Lists 40.6% Easy Longest Common Prefix 35.4% Easy Binary Tree Inorder Traversal 63.3% Medium Generate Parentheses 62.7% Medium Binary Search Tree Iterator 56.6% Medium Kth Largest Element in an Array 55.4% Medium Path Sum IV 54.7% Medium Unique Paths 54.1% Medium Decode String 50.0% Medium Number of Islands 46.8% Medium Split Array with Equal Sum 46.4% Medium Split Concatenated Strings 42.2% Medium Merge Intervals 39.3% Medium Search in Rotated Sorted Array 34.5% Medium Add Two Numbers 33.9% Medium LRU Cache 33.2% Medium Maximum Product Subarray 31.7% Medium Valid Parenthesis String 31.0% Medium Longest Substring Without Repeating Characters 30.4% Medium Longest Palindromic Substring 29.5% Medium 3Sum 26.8% Medium Subarrays with K Different Integers 48.6% Hard Sliding Window Maximum 43.0% Hard Merge k Sorted Lists 40.2% Hard LFU Cache 34.2% Hard Arithmetic Slices II - Subsequence 32.7% Hard Median of Two Sorted Arrays 29.6% Hard Regular Expression Matching 26.8% Hard