PayPal LeetCode Questions
105 questions all-time · 19 easy · 69 medium · 17 hard
| # | Problem | Difficulty | Frequency | Acceptance |
|---|---|---|---|---|
| 1 | Zigzag Conversion String | Medium | 100 | 0.5% |
| 2 | Minimum Absolute Difference Array, Sorting | Easy | 93 | 0.8% |
| 3 | Longest Increasing Subsequence Array, Binary Search, Dynamic Programming | Medium | 88 | 0.6% |
| 4 | LRU Cache Hash Table, Linked List, Design, Doubly-Linked List | Medium | 83 | 0.5% |
| 5 | Count Vowel Strings in Ranges Array, String, Prefix Sum | Medium | 83 | 0.7% |
| 6 | Find Words That Can Be Formed by Characters Array, Hash Table, String, Counting | Easy | 81 | 0.7% |
| 7 | Time Needed to Rearrange a Binary String String, Dynamic Programming, Simulation | Medium | 79 | 0.5% |
| 8 | Maximum Number of Integers to Choose From a Range I Array, Hash Table, Binary Search, Greedy, Sorting | Medium | 79 | 0.7% |
| 9 | Maximum Frequency Score of a Subarray Array, Hash Table, Math, Stack, Sliding Window | Hard | 79 | 0.4% |
| 10 | Meeting Scheduler Array, Two Pointers, Sorting | Medium | 79 | 0.6% |
| 11 | Minimum Non-Zero Product of the Array Elements Math, Greedy, Recursion | Medium | 77 | 0.4% |
| 12 | Word Search Array, String, Backtracking, Depth-First Search, Matrix | Medium | 77 | 0.5% |
| 13 | Smallest Greater Multiple Made of Two Digits Math, Enumeration | Medium | 77 | 0.5% |
| 14 | Number of Valid Move Combinations On Chessboard Array, String, Backtracking, Simulation | Hard | 77 | 0.5% |
| 15 | Number of Islands Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix | Medium | 77 | 0.6% |
| 16 | Count Array Pairs Divisible by K Array, Hash Table, Math, Counting, Number Theory | Hard | 77 | 0.3% |
| 17 | Count the Number of Vowel Strings in Range Array, String, Counting | Easy | 77 | 0.7% |
| 18 | Maximum Number of Integers to Choose From a Range II Array, Binary Search, Greedy, Sorting | Medium | 77 | 0.3% |
| 19 | Paint House III Array, Dynamic Programming | Hard | 77 | 0.6% |
| 20 | Maximum Sum Obtained of Any Permutation Array, Greedy, Sorting, Prefix Sum | Medium | 77 | 0.4% |
| 21 | Pythagorean Distance Nodes in a Tree Tree, Breadth-First Search | Medium | 77 | 0.6% |
| 22 | Product of Array Except Self Array, Prefix Sum | Medium | 74 | 0.7% |
| 23 | Maximal Square Array, Dynamic Programming, Matrix | Medium | 74 | 0.5% |
| 24 | Coin Change Array, Dynamic Programming, Breadth-First Search | Medium | 72 | 0.5% |
| 25 | Two Sum Array, Hash Table | Easy | 69 | 0.6% |
| 26 | Group Anagrams Array, Hash Table, String, Sorting | Medium | 69 | 0.7% |
| 27 | Merge Intervals Array, Sorting | Medium | 69 | 0.5% |
| 28 | Longest Substring Without Repeating Characters Hash Table, String, Sliding Window | Medium | 65 | 0.4% |
| 29 | Search in Rotated Sorted Array Array, Binary Search | Medium | 65 | 0.5% |
| 30 | Best Time to Buy and Sell Stock Array, Dynamic Programming | Easy | 65 | 0.6% |
| 31 | Find the Smallest Divisor Given a Threshold Array, Binary Search | Medium | 65 | 0.7% |
| 32 | Find Median from Data Stream Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream | Hard | 65 | 0.5% |
| 33 | Last Stone Weight Array, Heap (Priority Queue) | Easy | 65 | 0.7% |
| 34 | Pairs of Songs With Total Durations Divisible by 60 Array, Hash Table, Counting | Medium | 61 | 0.5% |
| 35 | House Robber Array, Dynamic Programming | Medium | 61 | 0.5% |
| 36 | Maximum Subarray Array, Divide and Conquer, Dynamic Programming | Medium | 61 | 0.5% |
| 37 | Maximum Number of Events That Can Be Attended Array, Greedy, Sorting, Heap (Priority Queue) | Medium | 61 | 0.4% |
| 38 | Asteroid Collision Array, Stack, Simulation | Medium | 61 | 0.5% |
| 39 | Top K Frequent Elements Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect | Medium | 56 | 0.7% |
| 40 | Subarray Sum Equals K Array, Hash Table, Prefix Sum | Medium | 56 | 0.5% |
| 41 | Random Pick with Weight Array, Math, Binary Search, Prefix Sum, Randomized | Medium | 56 | 0.5% |
| 42 | Palindromic Substrings Two Pointers, String, Dynamic Programming | Medium | 56 | 0.7% |
| 43 | Longest Consecutive Sequence Array, Hash Table, Union-Find | Medium | 56 | 0.5% |
| 44 | Valid Sudoku Array, Hash Table, Matrix | Medium | 56 | 0.6% |
| 45 | 3Sum Smaller Array, Two Pointers, Binary Search, Sorting | Medium | 56 | 0.5% |
| 46 | Smallest String With Swaps Array, Hash Table, String, Depth-First Search, Breadth-First Search, Union-Find, Sorting | Medium | 56 | 0.6% |
| 47 | Container With Most Water Array, Two Pointers, Greedy | Medium | 49 | 0.6% |
| 48 | Valid Parentheses String, Stack | Easy | 49 | 0.4% |
| 49 | Trapping Rain Water Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack | Hard | 49 | 0.7% |
| 50 | Count Vowel Substrings of a String Hash Table, String | Easy | 49 | 0.7% |
| 51 | Loud and Rich Array, Depth-First Search, Graph Theory, Topological Sort | Medium | 49 | 0.6% |
| 52 | Minimum Increment to Make Array Unique Array, Greedy, Sorting, Counting | Medium | 49 | 0.6% |
| 53 | Find Peak Element Array, Binary Search | Medium | 49 | 0.5% |
| 54 | Degree of an Array Array, Hash Table | Easy | 49 | 0.6% |
| 55 | Spiral Matrix Array, Matrix, Simulation | Medium | 49 | 0.6% |
| 56 | Koko Eating Bananas Array, Binary Search | Medium | 49 | 0.5% |
| 57 | LFU Cache Hash Table, Linked List, Design, Doubly-Linked List | Hard | 49 | 0.5% |
| 58 | Reaching Points Math | Hard | 49 | 0.3% |
| 59 | Subsets Array, Backtracking, Bit Manipulation | Medium | 49 | 0.8% |
| 60 | Remove All Adjacent Duplicates in String II String, Stack | Medium | 49 | 0.6% |
| 61 | Top K Frequent Words Array, Hash Table, String, Trie, Sorting, Heap (Priority Queue), Bucket Sort, Counting | Medium | 49 | 0.6% |
| 62 | Average Selling Price Database | Easy | 49 | 0.4% |
| 63 | Median of Two Sorted Arrays Array, Binary Search, Divide and Conquer | Hard | 40 | 0.5% |
| 64 | 3Sum Array, Two Pointers, Sorting | Medium | 40 | 0.4% |
| 65 | Find First and Last Position of Element in Sorted Array Array, Binary Search | Medium | 40 | 0.5% |
| 66 | Sort Colors Array, Two Pointers, Sorting | Medium | 40 | 0.7% |
| 67 | Maximum Product Subarray Array, Dynamic Programming | Medium | 40 | 0.4% |
| 68 | Valid Anagram Hash Table, String, Sorting | Easy | 40 | 0.7% |
| 69 | Minimum Replacements to Sort the Array Array, Math, Greedy | Hard | 40 | 0.5% |
| 70 | Text Justification Array, String, Simulation | Hard | 40 | 0.5% |
| 71 | Design Twitter Hash Table, Linked List, Design, Heap (Priority Queue) | Medium | 40 | 0.4% |
| 72 | Rotate Image Array, Math, Matrix | Medium | 40 | 0.8% |
| 73 | Kth Largest Element in an Array Array, Divide and Conquer, Sorting, Heap (Priority Queue), Quickselect | Medium | 40 | 0.7% |
| 74 | Minimum Number of Removals to Make Mountain Array Array, Binary Search, Dynamic Programming, Greedy | Hard | 40 | 0.5% |
| 75 | Minimum Number of Swaps to Make the String Balanced Two Pointers, String, Stack, Greedy | Medium | 40 | 0.8% |
| 76 | Divide Players Into Teams of Equal Skill Array, Hash Table, Two Pointers, Sorting | Medium | 40 | 0.7% |
| 77 | First Missing Positive Array, Hash Table | Hard | 40 | 0.4% |
| 78 | Merge In Between Linked Lists Linked List | Medium | 40 | 0.8% |
| 79 | Lexicographically Smallest Palindrome Two Pointers, String, Greedy | Easy | 40 | 0.8% |
| 80 | Flatten Deeply Nested Array | Medium | 40 | 0.7% |
| 81 | Jump Game Array, Dynamic Programming, Greedy | Medium | 40 | 0.4% |
| 82 | Happy Number Hash Table, Math, Two Pointers | Easy | 40 | 0.6% |
| 83 | Course Schedule Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort | Medium | 40 | 0.5% |
| 84 | Search a 2D Matrix II Array, Binary Search, Divide and Conquer, Matrix | Medium | 40 | 0.6% |
| 85 | Binary Tree Maximum Path Sum Dynamic Programming, Tree, Depth-First Search, Binary Tree | Hard | 40 | 0.4% |
| 86 | Move Zeroes Array, Two Pointers | Easy | 40 | 0.6% |
| 87 | Rotting Oranges Array, Breadth-First Search, Matrix | Medium | 40 | 0.6% |
| 88 | Swap Nodes in Pairs Linked List, Recursion | Medium | 40 | 0.7% |
| 89 | Search Suggestions System Array, String, Binary Search, Trie, Sorting, Heap (Priority Queue) | Medium | 40 | 0.7% |
| 90 | Longest Substring Of All Vowels in Order String, Sliding Window | Medium | 40 | 0.5% |
| 91 | Serialize and Deserialize Binary Tree String, Tree, Depth-First Search, Breadth-First Search, Design, Binary Tree | Hard | 40 | 0.6% |
| 92 | Climbing Stairs Math, Dynamic Programming, Memoization | Easy | 40 | 0.5% |
| 93 | Missing Element in Sorted Array Array, Binary Search | Medium | 40 | 0.6% |
| 94 | Fizz Buzz Math, String, Simulation | Easy | 40 | 0.8% |
| 95 | Nearest Exit from Entrance in Maze Array, Breadth-First Search, Matrix | Medium | 40 | 0.5% |
| 96 | Maximum Population Year Array, Counting, Prefix Sum | Easy | 40 | 0.6% |
| 97 | Longest String Chain Array, Hash Table, Two Pointers, String, Dynamic Programming, Sorting | Medium | 40 | 0.6% |
| 98 | Minimum Edge Reversals So Every Node Is Reachable Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory | Hard | 40 | 0.6% |
| 99 | Insert Interval Array | Medium | 40 | 0.5% |
| 100 | Best Time to Buy and Sell Stock III Array, Dynamic Programming | Hard | 40 | 0.5% |
| 101 | Longest Palindromic Substring Two Pointers, String, Dynamic Programming | Medium | 40 | 0.4% |
| 102 | First Unique Character in a String Hash Table, String, Queue, Counting | Easy | 40 | 0.7% |
| 103 | Combination Sum Array, Backtracking | Medium | 40 | 0.8% |
| 104 | Find the Index of the First Occurrence in a String Two Pointers, String, String Matching | Easy | 40 | 0.5% |
| 105 | Non-overlapping Intervals Array, Dynamic Programming, Greedy, Sorting | Medium | 40 | 0.6% |
How to read this list
The tabs at the top split the questions by how recently people said they were asked in interviews. "Last 30 Days" is the past month, "Last 3 Months" is the past quarter, and so on. "All Time" is every question on record for this company.
Frequency is a score from 0 to 100 for how often a question showed up in that time window. A higher number means it came up more often, so the list starts with the most common questions first. Acceptance is the share of submissions that pass on LeetCode. Click any question to open it on LeetCode.