ServiceNow LeetCode Questions
71 questions all-time · 7 easy · 51 medium · 13 hard
| # | Problem | Difficulty | Frequency | Acceptance |
|---|---|---|---|---|
| 1 | LRU Cache Hash Table, Linked List, Design, Doubly-Linked List | Medium | 100 | 0.5% |
| 2 | Longest Substring Without Repeating Characters Hash Table, String, Sliding Window | Medium | 95 | 0.4% |
| 3 | Lexicographically Smallest String After Operations With Constraint String, Greedy | Medium | 95 | 0.6% |
| 4 | Number of Distinct Roll Sequences Dynamic Programming, Memoization | Hard | 95 | 0.6% |
| 5 | Find Minimum Diameter After Merging Two Trees Tree, Depth-First Search, Breadth-First Search, Graph Theory | Hard | 95 | 0.6% |
| 6 | Trapping Rain Water Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack | Hard | 89 | 0.7% |
| 7 | Maximum Score with Co-Prime Element Array, Hash Table, Math, Combinatorics, Enumeration, Number Theory | Hard | 89 | 0.3% |
| 8 | Number of Islands Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix | Medium | 86 | 0.6% |
| 9 | Generate Parentheses String, Dynamic Programming, Backtracking | Medium | 82 | 0.8% |
| 10 | String Compression Two Pointers, String | Medium | 82 | 0.6% |
| 11 | Valid Parentheses String, Stack | Easy | 77 | 0.4% |
| 12 | Longest Repeating Character Replacement Hash Table, String, Sliding Window | Medium | 77 | 0.6% |
| 13 | Container With Most Water Array, Two Pointers, Greedy | Medium | 71 | 0.6% |
| 14 | First Missing Positive Array, Hash Table | Hard | 71 | 0.4% |
| 15 | Asteroid Collision Array, Stack, Simulation | Medium | 71 | 0.5% |
| 16 | Sliding Window Maximum Array, Queue, Sliding Window, Heap (Priority Queue), Monotonic Queue | Hard | 71 | 0.5% |
| 17 | Pacific Atlantic Water Flow Array, Depth-First Search, Breadth-First Search, Matrix | Medium | 71 | 0.6% |
| 18 | Best Time to Buy and Sell Stock II Array, Dynamic Programming, Greedy | Medium | 71 | 0.7% |
| 19 | Two Sum Array, Hash Table | Easy | 63 | 0.6% |
| 20 | Longest Palindromic Substring Two Pointers, String, Dynamic Programming | Medium | 63 | 0.4% |
| 21 | Group Anagrams Array, Hash Table, String, Sorting | Medium | 63 | 0.7% |
| 22 | Maximum Subarray Array, Divide and Conquer, Dynamic Programming | Medium | 63 | 0.5% |
| 23 | Best Time to Buy and Sell Stock Array, Dynamic Programming | Easy | 63 | 0.6% |
| 24 | Kth Largest Element in an Array Array, Divide and Conquer, Sorting, Heap (Priority Queue), Quickselect | Medium | 63 | 0.7% |
| 25 | Move Zeroes Array, Two Pointers | Easy | 63 | 0.6% |
| 26 | Number of Visible People in a Queue Array, Stack, Monotonic Stack | Hard | 63 | 0.7% |
| 27 | Coin Change Array, Dynamic Programming, Breadth-First Search | Medium | 63 | 0.5% |
| 28 | Rotting Oranges Array, Breadth-First Search, Matrix | Medium | 63 | 0.6% |
| 29 | Reverse Words in a String II Two Pointers, String | Medium | 63 | 0.6% |
| 30 | LFU Cache Hash Table, Linked List, Design, Doubly-Linked List | Hard | 63 | 0.5% |
| 31 | Set Matrix Zeroes Array, Hash Table, Matrix | Medium | 63 | 0.6% |
| 32 | Check if a Parentheses String Can Be Valid String, Stack, Greedy | Medium | 63 | 0.5% |
| 33 | Minimum Number of Swaps to Make the String Balanced Two Pointers, String, Stack, Greedy | Medium | 63 | 0.8% |
| 34 | Jump Game II Array, Dynamic Programming, Greedy | Medium | 63 | 0.4% |
| 35 | Merge Two Sorted Lists Linked List, Recursion | Easy | 63 | 0.7% |
| 36 | Median of Two Sorted Arrays Array, Binary Search, Divide and Conquer | Hard | 53 | 0.5% |
| 37 | Zigzag Conversion String | Medium | 53 | 0.5% |
| 38 | Merge Intervals Array, Sorting | Medium | 53 | 0.5% |
| 39 | Vowels of All Substrings Math, String, Dynamic Programming, Combinatorics | Medium | 53 | 0.6% |
| 40 | Maximum Product Subarray Array, Dynamic Programming | Medium | 53 | 0.4% |
| 41 | Largest Number Array, String, Greedy, Sorting | Medium | 53 | 0.4% |
| 42 | Reverse Linked List Linked List, Recursion | Easy | 53 | 0.8% |
| 43 | Daily Temperatures Array, Stack, Monotonic Stack | Medium | 53 | 0.7% |
| 44 | Minimum One Bit Operations to Make Integers Zero Math, Dynamic Programming, Bit Manipulation, Recursion, Memoization | Hard | 53 | 0.8% |
| 45 | Pow(x, n) Math, Recursion | Medium | 53 | 0.4% |
| 46 | Amount of Time for Binary Tree to Be Infected Hash Table, Tree, Depth-First Search, Breadth-First Search, Binary Tree | Medium | 53 | 0.7% |
| 47 | Time Needed to Rearrange a Binary String String, Dynamic Programming, Simulation | Medium | 53 | 0.5% |
| 48 | Binary Tree Right Side View Tree, Depth-First Search, Breadth-First Search, Binary Tree | Medium | 53 | 0.7% |
| 49 | Letter Combinations of a Phone Number Hash Table, String, Backtracking | Medium | 53 | 0.7% |
| 50 | Palindrome Linked List Linked List, Two Pointers, Stack, Recursion | Easy | 53 | 0.6% |
| 51 | 4Sum Array, Two Pointers, Sorting | Medium | 53 | 0.4% |
| 52 | Number of Distinct Islands Array, Hash Table, Depth-First Search, Breadth-First Search, Union-Find, Sorting, Matrix, Hash Function | Medium | 53 | 0.6% |
| 53 | Next Permutation Array, Two Pointers | Medium | 53 | 0.5% |
| 54 | Gas Station Array, Greedy | Medium | 53 | 0.5% |
| 55 | Find Peak Element Array, Binary Search | Medium | 53 | 0.5% |
| 56 | Target Sum Array, Dynamic Programming, Backtracking | Medium | 53 | 0.5% |
| 57 | Single Element in a Sorted Array Array, Binary Search | Medium | 53 | 0.6% |
| 58 | Top K Frequent Elements Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect | Medium | 53 | 0.7% |
| 59 | Subarrays with K Different Integers Array, Hash Table, Sliding Window, Counting | Hard | 53 | 0.7% |
| 60 | House Robber II Array, Dynamic Programming | Medium | 53 | 0.5% |
| 61 | Maximum Profit From Trading Stocks Array, Dynamic Programming | Medium | 53 | 0.5% |
| 62 | Subarray Sum Equals K Array, Hash Table, Prefix Sum | Medium | 53 | 0.5% |
| 63 | Next Greater Element II Array, Stack, Monotonic Stack | Medium | 53 | 0.7% |
| 64 | Word Ladder Hash Table, String, Breadth-First Search | Hard | 53 | 0.5% |
| 65 | Simplify Path String, Stack | Medium | 53 | 0.5% |
| 66 | Fruit Into Baskets Array, Hash Table, Sliding Window | Medium | 53 | 0.5% |
| 67 | Longest Common Subsequence String, Dynamic Programming | Medium | 53 | 0.6% |
| 68 | Combination Sum Array, Backtracking | Medium | 53 | 0.8% |
| 69 | Critical Connections in a Network Depth-First Search, Graph Theory, Biconnected Component | Hard | 53 | 0.6% |
| 70 | Reverse Words in a String Two Pointers, String | Medium | 53 | 0.6% |
| 71 | Sort Colors Array, Two Pointers, Sorting | Medium | 53 | 0.7% |
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.