| 2D Array - Hourglass Sum | easy | array |
| Backspace String Compare | easy | two-pointers string stack simulation |
| Binary Search | easy | array binary-search |
| Check if All Characters Have Equal Number of Occurrences | easy | hash-table string counting |
| Check If Sentence Is Pangram | easy | hash-table string |
| Combine Two Sorted Array | easy | two-pointers |
| Contiguous Array | medium | array hash-table prefix-sum |
| Count Number of Nice Subarrays | medium | array hash-table math sliding-window prefix-sum |
| Counting Elements | easy | array hash-table |
| Equal Row and Column Pairs | medium | array hash-table matrix simulation |
| Find Lonely Numbers | easy | array hash-table |
| Find Pivot Index | easy | array |
| Find Players With Zero or One Losses | medium | array hash-table sorting counting |
| Find the Highest Altitude | easy | array |
| First Letter to Appear Twice | easy | hash-table string bit-manipulation counting |
| Get Equal Substrings Within Budget | medium | sliding-window |
| Group Anagrams | medium | array hash-table string sorting |
| Intersection of Multiple Arrays | easy | array hash-table sorting counting |
| Is Subsequence | easy | two-pointers |
| Jewels and Stones | easy | hash-table string |
| K Radius Subarray Averages | medium | prefix-sum |
| Koko Eating Bananas | medium | array binary-search |
| Kth Node From End of Linked List | easy | linked-list two-pointers |
| Largest Unique Number | easy | array hash-table sorting |
| Linked List Cycle | easy | hash-table linked-list two-pointers |
| Longest Ones After One Flip | medium | sliding-window |
| Longest Subarray Sum Less Equal To Target | medium | sliding-window |
| Longest Subsequence With Limited Sum | easy | array binary-search greedy sorting prefix-sum |
| Longest Substring With At Most K Distinct Characters | medium | hash-table string sliding-window |
| Longest Substring Without Repeating Characters | medium | hash-table string sliding-window |
| Max Average Subarray | easy | sliding-window |
| Max Consecutive Ones III | medium | sliding-window |
| Max Sum of a Pair With Equal Sum of Digits | medium | array hash-table sorting heap-priority-queue |
| Max Sum Subarray Of Size K | easy | sliding-window |
| Maximum Number of Balloons | easy | hash-table string counting |
| Maximum Number of Vowels in a Substring of Given Length | medium | sliding-window |
| Maximum Twin Sum of a Linked List | medium | linked-list two-pointers stack |
| Middle of the Linked List | easy | linked-list two-pointers |
| Minimum Common Value | easy | two-pointers |
| Minimum Consecutive Cards to Pick Up | medium | array hash-table sliding-window |
| Minimum Size Subarray Sum | medium | sliding-window |
| Minimum Value to Get Positive Step by Step Sum | easy | prefix-sum |
| Missing Number | easy | array hash-table math bit-manipulation |
| Move Zeroes | easy | two-pointers |
| Number of Ways to Split Array | medium | prefix-sum |
| Palindrome | easy | two-pointers |
| Range Sum Queries | easy | prefix-sum |
| Range Sum Query - Immutable | easy | array design prefix-sum |
| Ransom Note | easy | hash-table string counting |
| Remove All Adjacent Duplicates In String | easy | string stack |
| Remove Duplicates from Sorted List | easy | linked-list two-pointers |
| Reverse Linked List II | medium | linked-list |
| Reverse Only Letters | easy | two-pointers |
| Reverse Prefix of Word | easy | two-pointers |
| Reverse String | easy | two-pointers |
| Reverse Words in a String III | easy | two-pointers |
| Running Sum of 1d Array | easy | prefix-sum |
| Search a 2D Matrix | medium | array binary-search matrix |
| Search Insert Position | easy | array binary-search |
| Simplify Path | medium | string stack |
| Square Of Sorted Array | easy | two-pointers |
| Subarray Product Less Than K | medium | sliding-window |
| Subarray Sum Equals K | medium | array hash-table prefix-sum |
| Successful Pairs of Spells and Potions | medium | array two-pointers binary-search sorting prefix-sum |
| Swap Nodes in Pairs | medium | linked-list recursion two-pointers |
| Two Sum | easy | array hash-table |
| Two Sum Sorted | medium | two-pointers |
| Valid Parentheses | easy | string stack |