python problem-solving using popular algorithms (mostly leetcode)

Easy:

• Min Cost Climbing Stairs (https://leetcode.com/problems/min-cost-climbing-stairs/)
• Lemonade Change (https://leetcode.com/problems/lemonade-change/)
• Base 7 (https://leetcode.com/problems/base-7/)
• Sort Colors (https://leetcode.com/problems/sort-colors/submissions/)
• Add Strings (https://leetcode.com/problems/add-strings/)
• Leftmost Column with at least a One (https://leetcode.com/problems/leftmost-column-with-at-least-a-one/submissions)
• Add Binary (https://leetcode.com/problems/add-binary/)
• Maximum Number of Coins (https://leetcode.com/problems/maximum-number-of-coins-you-can-get/)
• Thousand Separator (https://leetcode.com/problems/thousand-separator)
• Make the String Great (https://leetcode.com/problems/make-the-string-great/)
• Valid Palindrome II (https://leetcode.com/problems/valid-palindrome-ii/)
• Kids With the Greatest Number of Candies (https://leetcode.com/problems/kids-with-the-greatest-number-of-candies/)
• Palindrome Permutation (https://leetcode.com/problems/palindrome-permutation/)
• Number of Good Pairs (https://leetcode.com/problems/number-of-good-pairs/)
• Invert Binary Tree (https://leetcode.com/problems/invert-binary-tree/)
• Verifying an Alien Dictionary (https://leetcode.com/problems/verifying-an-alien-dictionary/)
• Convert a Number to Hexadecimal (https://leetcode.com/problems/convert-a-number-to-hexadecimal/)
• Two Sum (https://leetcode.com/problems/two-sum/)
• Two Sum 2 (Same but runs in O(n))
• Valid Palindrome (https://leetcode.com/problems/valid-palindrome/)
• Jewels and Stones (https://leetcode.com/problems/jewels-and-stones/description/)
• Middle of the Linked List (https://leetcode.com/problems/middle-of-the-linked-list/description/)
• Goat Latin (https://leetcode.com/problems/goat-latin/description/)
• Hamming Distance (https://leetcode.com/problems/hamming-distance/)
• Binary Gap (https://leetcode.com/problems/binary-gap/description/)
• Wiggle Sort II (https://leetcode.com/problems/wiggle-sort-ii/description/)
• Min Stack (https://leetcode.com/problems/min-stack/description/)
• Binary Search (https://leetcode.com/problems/min-stack/description/)
• Valid Parentheses (https://leetcode.com/problems/valid-parentheses/solution/)
• First Unique Character in a String (https://leetcode.com/problems/first-unique-character-in-a-string/)
• Plus One (https://leetcode.com/problems/plus-one/)
• Unique Email Addresses (https://leetcode.com/problems/unique-email-addresses)
• Reverse Vowels of a String (https://leetcode.com/problems/reverse-vowels-of-a-string)
• Robot Return to Origin (https://leetcode.com/problems/robot-return-to-origin/)
• Island Perimeter (https://leetcode.com/problems/island-perimeter/)
• Reverse Integer (https://leetcode.com/problems/reverse-integer/)
• License Key Formatting (https://leetcode.com/problems/license-key-formatting/)
• Flood Fill (https://leetcode.com/problems/flood-fill/)
• Find All Numbers Disappeared in an Array (https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/)
• Best Time to Buy and Sell Stocks (https://leetcode.com/problems/best-time-to-buy-and-sell-stock/)
• Best Time to Buy and Sell Stocks II (https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/)
• Fizz-Buzz (https://leetcode.com/problems/fizz-buzz/)
• Ransom Note (https://leetcode.com/problems/ransom-note)
• Palindrome Number (https://leetcode.com/problems/palindrome-number/)
• Fibonacci with and without Memoization
• Binary Search (https://leetcode.com/problems/binary-search/)
• Autocomplete (Daily Coding Problem #11)
• Roman To Integer (https://leetcode.com/problems/roman-to-integer))
• Add Digits
• Missing Number (https://leetcode.com/problems/missing-number/)
• Climbing Stairs (https://leetcode.com/problems/climbing-stairs/)
• Move Zeroes (https://leetcode.com/problems/move-zeroes/)
• Best Subway Seat
• Merge Intervals
• Reverse String (https://leetcode.com/problems/reverse-string/)
• Valid Anagram (https://leetcode.com/problems/valid-anagram/)
• Intersection of two Arrays (https://leetcode.com/problems/intersection-of-two-arrays/)
• Hamming Distance (https://leetcode.com/problems/hamming-distance/)
• First Bad Version (https://leetcode.com/problems/first-bad-version/)
• Longest Common Prefix (https://leetcode.com/problems/longest-common-prefix/)
• Backspace String Compare (https://leetcode.com/problems/backspace-string-compare/)
• Meeting Rooms (https://leetcode.com/problems/meeting-rooms/submissions/)
• Remove Duplicates From Sorted Array (https://leetcode.com/problems/remove-duplicates-from-sorted-array)
• Combine Two Tables (https://leetcode.com/problems/combine-two-tables)
• Majority Element (https://leetcode.com/problems/majority-element/)
• Sort Array By Parity
• Flipping An Image (https://leetcode.com/problems/flipping-an-image/)
• Maximum Subarray (https://leetcode.com/problems/maximum-subarray/)
• Stack Implementation and Stack Sorting
• Rotate Image (https://leetcode.com/problems/rotate-image/solution/)
• Find First Positive Number (https://www.geeksforgeeks.org/find-the-point-where-a-function-becomes-negative/)
• Recursively Sum Up to Target
• Most Common Word (https://leetcode.com/problems/most-common-word/)
• Detect Capital (https://leetcode.com/problems/detect-capital/)
• Same Tree (https://leetcode.com/problems/same-tree/)
• House Robber (https://leetcode.com/problems/house-robber/)
• Maximize Distance to Closest Person (https://leetcode.com/problems/maximize-distance-to-closest-person)
• Binary Tree Level order Traversal II (https://leetcode.com/problems/binary-tree-level-order-traversal-ii/)
• Average of Levels in Binary Tree (https://leetcode.com/problems/average-of-levels-in-binary-tree)
• Sum of Left Leaves (https://leetcode.com/problems/sum-of-left-leaves)
• Find Pivot Index (https://leetcode.com/problems/find-pivot-index/)
• Search Insert Position (https://leetcode.com/problems/search-insert-position/)
• Guess Number Higher or Lower (https://leetcode.com/problems/guess-number-higher-or-lower/)
• Range Sum of BST (https://leetcode.com/problems/range-sum-of-bst/)
• To Lower Case (https://leetcode.com/problems/to-lower-case/)
• Unique Morse Code Words (https://leetcode.com/problems/unique-morse-code-words)
• Squares of a Sorted Array (https://leetcode.com/problems/squares-of-a-sorted-array/)
• N-Repeated Element in Size 2N Array (https://leetcode.com/problems/n-repeated-element-in-size-2n-array/)
• Path Sum (https://leetcode.com/problems/path-sum)
• Next Greater Element (https://leetcode.com/problems/next-greater-element-i)
• Find Common Characters (https://leetcode.com/problems/find-common-characters)
• Intersection of Two Arrays II (https://leetcode.com/problems/intersection-of-two-arrays-ii/)
• Delete a Node in a Linked List (https://leetcode.com/problems/delete-node-in-a-linked-list)
• Linked List Cycle (https://leetcode.com/problems/linked-list-cycle/)
• Reverse Linked List (https://leetcode.com/problems/reverse-linked-list/)
• Occurences After Bigram (https://leetcode.com/problems/occurrences-after-bigram/)
• Fixed Point (https://leetcode.com/problems/fixed-point/)
• Student Attendance Record I (https://leetcode.com/problems/student-attendance-record-i/)
• Sum of Even Numbers After Queries (https://leetcode.com/problems/sum-of-even-numbers-after-queries/)
• Fibonacci Number (https://leetcode.com/problems/fibonacci-number/)
• Last Stone Weight (https://leetcode.com/problems/last-stone-weight)
• Insert Delete GetRandom O(1) (https://leetcode.com/problems/insert-delete-getrandom-o1)
• Array Partition (https://leetcode.com/problems/array-partition-i/)
• Shortest Unsorted Continuous Subarray (https://leetcode.com/problems/shortest-unsorted-continuous-subarray/)
• Single Number (https://leetcode.com/problems/single-number/)
• High Five (https://leetcode.com/problems/high-five/)
• Max Consecutive Ones (https://leetcode.com/problems/max-consecutive-ones/)
• Plus One Linked List (https://leetcode.com/problems/plus-one-linked-list/)
• Nim Game (https://leetcode.com/problems/nim-game/)
• Remove Duplicates From Sorted List (https://leetcode.com/problems/remove-duplicates-from-sorted-list/)
• Remove Linked List Elements (https://leetcode.com/problems/remove-linked-list-elements/)
• Palindrome Linked List (https://leetcode.com/problems/palindrome-linked-list/)
• Reverse Only Letters (https://leetcode.com/problems/reverse-only-letters)
• Remove Outer Parentheses (https://leetcode.com/problems/remove-outermost-parentheses)
• Sum of Digits in the Minimum Number (https://leetcode.com/problems/sum-of-digits-in-the-minimum-number/)
• Monotonic Array (https://leetcode.com/problems/monotonic-array/)
• DI String Match (https://leetcode.com/problems/di-string-match)
• Contains Duplicates (https://leetcode.com/problems/contains-duplicate)
• Contains Duplicate II (https://leetcode.com/problems/contains-duplicate-ii/)
• Find the Difference (https://leetcode.com/problems/find-the-difference/)
• Defanging an IP Address (https://leetcode.com/problems/defanging-an-ip-address/)
• Self Dividing Numbers (https://leetcode.com/problems/self-dividing-numbers)
• Intersection of two Linked Lists (https://leetcode.com/problems/intersection-of-two-linked-lists)
• Reverse Words in a String (https://leetcode.com/problems/reverse-words-in-a-string-iii/)
• Remove Vowels From a String (https://leetcode.com/problems/remove-vowels-from-a-string/)
• Number Complement (https://leetcode.com/problems/number-complement/)
• Leaf-Similiar Trees (https://leetcode.com/problems/leaf-similar-trees/)
• Binary Tree and Linked List Traversal Examples
• Merge Two Binary Trees (https://leetcode.com/problems/merge-two-binary-trees/)
• N-ary Tree Preorder Traversal (https://leetcode.com/problems/n-ary-tree-preorder-traversal/)
• N-ary Tree Postorder Traversal (https://leetcode.com/problems/n-ary-tree-postorder-traversal/)
• Reorder Log Files (https://leetcode.com/problems/reorder-log-files/)
• Two Sum II - Input Array is Sorted (https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/)
• Implement strStr() (https://leetcode.com/problems/implement-strstr/)
• Distribute Candies to People (https://leetcode.com/problems/distribute-candies-to-people/)
• Keyboard Row (https://leetcode.com/problems/keyboard-row/)
• Largest Unique Number (https://leetcode.com/contest/biweekly-contest-5/problems/largest-unique-number/)
• Minimum Moves to Equal Array Elements (https://leetcode.com/problems/minimum-moves-to-equal-array-elements/)
• Rotate String (https://leetcode.com/problems/rotate-string)
• Armstrong Number (https://leetcode.com/problems/armstrong-number/)
• Max Stack (https://leetcode.com/problems/max-stack/)
• Peak Index in a Mountain Array (https://leetcode.com/problems/peak-index-in-a-mountain-array/)
• Confusing Number (https://leetcode.com/problems/confusing-number)
• Delete Columns to Make Sorted (https://leetcode.com/problems/delete-columns-to-make-sorted)
• Maximum Product of Three Numbers (https://leetcode.com/problems/maximum-product-of-three-numbers/)
• Add to Array Form (https://leetcode.com/problems/add-to-array-form-of-integer/)
• Find Smallest Letter Greater Than Target (https://leetcode.com/problems/find-smallest-letter-greater-than-target)
• Add Digits (https://leetcode.com/problems/add-digits/)
• Check if a Number is Majority Element in a Sorted Array (https://leetcode.com/problems/check-if-a-number-is-majority-element-in-a-sorted-array/)
• Search in a Binary Search Tree (https://leetcode.com/problems/search-in-a-binary-search-tree/)
• Shortest Distance to a Character (https://leetcode.com/problems/shortest-distance-to-a-character/)
• Vending Machine with Change Code (Return Change)
• Maximum Depth of Binary Tree (https://leetcode.com/problems/maximum-depth-of-binary-tree)
• Univalued Binary Tree (https://leetcode.com/problems/univalued-binary-tree/)
• Maximum Depth of N-Ary Tree (https://leetcode.com/problems/maximum-depth-of-n-ary-tree/)
• N-Ary Tree Level Order Traversal (N-Ary Tree Level Order Traversal (https://leetcode.com/problems/n-ary-tree-level-order-traversal/)
• Sum of Root to Leaf Binary Numbers (https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers/)
• Minimum Depth of Binary Tree (https://leetcode.com/problems/minimum-depth-of-binary-tree/)
• N-th Tribonacci Number (https://leetcode.com/problems/n-th-tribonacci-number/
• Two Sum Less Than K (https://leetcode.com/problems/two-sum-less-than-k/)
• Minimum Absolute Difference in BST (https://leetcode.com/problems/minimum-absolute-difference-in-bst/)
• Logger Rate Limiter (https://leetcode.com/problems/logger-rate-limiter/))
• Strobogrammatic Number (https://leetcode.com/problems/strobogrammatic-number/)
• Single-Row Keyboard (https://leetcode.com/problems/single-row-keyboard/)
• Positions of Large Groups (Positions of Large Groups (https://leetcode.com/problems/positions-of-large-groups/))
• Find Words that can be Formed by Characters (Find Words that can be Formed by Characters (https://leetcode.com/problems/find-words-that-can-be-formed-by-characters/))
• Number of Recent Calls (Number of Recent Calls (https://leetcode.com/problems/number-of-recent-calls))
• Nested List Weight (https://leetcode.com/problems/nested-list-weight-sum)
• Relative Sort Array (https://leetcode.com/problems/relative-sort-array/)
• Sort Array by Parity II (https://leetcode.com/problems/sort-array-by-parity-ii/)
• Longest Continuous Increasing Subsequence (https://leetcode.com/problems/longest-continuous-increasing-subsequence)
• Rotated Digits (https://leetcode.com/problems/rotated-digits)
• Available Captures for Rook (https://leetcode.com/problems/available-captures-for-rook/)
• Compare Strings by Frequency of the Smallest Character (https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character/)
• Counting Bits (Counting Bits (https://leetcode.com/problems/counting-bits)
• Matrix Cells in Distance Order (https://leetcode.com/problems/matrix-cells-in-distance-order)
• Remove All Adjacent Duplicates in String (https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string/)
• Shortest Word Distance (https://leetcode.com/problems/shortest-word-distance/)
• Maximum Swap (https://leetcode.com/problems/maximum-swap/)
• Pairs of Songs With Total Durations Divisible by 60 (https://leetcode.com/problems/pairs-of-songs-with-total-durations-divisible-by-60/)
• Count Substrings With Only One Distinct Letter (https://leetcode.com/problems/count-substrings-with-only-one-distinct-letter/)
• Two City Scheduling (https://leetcode.com/problems/two-city-scheduling)
• Closest Binary Search Tree Value (Closest Binary Search Tree Value (https://leetcode.com/problems/closest-binary-search-tree-value/))
• Maximum Number of Balloons (https://leetcode.com/problems/maximum-number-of-balloons/)
• Duplicate Zeros (https://leetcode.com/problems/duplicate-zeros)
• Distance Between Bus Stops (https://leetcode.com/problems/distance-between-bus-stops/)
• Uncommon Words from Two Sentences (https://leetcode.com/problems/uncommon-words-from-two-sentences/)
• How Many Apples Can You Put Into the Basket (https://leetcode.com/problems/how-many-apples-can-you-put-into-the-basket/)
• Minimum Absolute Difference (https://leetcode.com/problems/minimum-absolute-difference/)
• Can Place Flowers (https://leetcode.com/problems/can-place-flowers/)
• Unique Number of Occurrences (https://leetcode.com/problems/unique-number-of-occurrences/)
• Number of Lines to Write String (https://leetcode.com/problems/number-of-lines-to-write-string/)
• Intersection of Three Sorted Arrays (https://leetcode.com/problems/intersection-of-three-sorted-arrays/)
• Play With Chips (https://leetcode.com/problems/play-with-chips/)
• Split a String in Balanced Strings (https://leetcode.com/problems/split-a-string-in-balanced-strings/)
• Missing Number in Arithmetic Progression (https://leetcode.com/problems/missing-number-in-arithmetic-progression/)
• Sentence Similarity (https://leetcode.com/problems/sentence-similarity/)
• Find Positive Integer Solution For a Given Equation (https://leetcode.com/problems/find-positive-integer-solution-for-a-given-equation/)
• Partition Labels (https://leetcode.com/problems/partition-labels/)
• Array Transformation (https://leetcode.com/problems/array-transformation/)
• Subtree of Another Tree (https://leetcode.com/problems/subtree-of-another-tree/)
• Linked List Components (https://leetcode.com/problems/linked-list-components/)
• Binary Tree Paths (https://leetcode.com/problems/binary-tree-paths/)
• Cells With Odd Values in a Matrix (https://leetcode.com/problems/cells-with-odd-values-in-a-matrix)
• Encode Number (https://leetcode.com/problems/encode-number/)
• Repeated String Match (https://leetcode.com/problems/repeated-string-match/)
• Replace Elements with Greatest Element on Right Side (Replace Elements with Greatest Element on Right Side (https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side/))
• Sort Integers by the Number of 1 Bits (https://leetcode.com/problems/sort-integers-by-the-number-of-1-bits/)
• Generate a String with Characters that Have Odd Counts (https://leetcode.com/problems/generate-a-string-with-characters-that-have-odd-counts/)
• Increasing Decreasing String (https://leetcode.com/problems/increasing-decreasing-string/)
• XOR Operation in an Array (https://leetcode.com/problems/xor-operation-in-an-array/)

Medium:

• Delete Nodes And Return Forest
• Rank Teams by Votes (https://leetcode.com/problems/rank-teams-by-votes/)
• Clone Graph (https://leetcode.com/problems/clone-graph/)
• Next Permutation (https://leetcode.com/problems/next-permutation)
• Strings Differ by One Character (https://leetcode.com/problems/strings-differ-by-one-character/)
• Peeking Iterator (https://leetcode.com/problems/peeking-iterator/)
• Group Anagrams (https://leetcode.com/problems/group-anagrams/)
• Meeting Scheduler (https://leetcode.com/problems/meeting-scheduler/)
• Validate Stack Sequences (https://leetcode.com/problems/validate-stack-sequences/)
• Binary Tree Zigzag Level Order Traversal (https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/
• Encode and Decode TinyURL (https://leetcode.com/problems/encode-and-decode-tinyurl/description/)
• Bubble Sort (see wikipedia: https://en.wikipedia.org/wiki/Bubble_sort)
• Meeting Rooms II (https://leetfree.com/problems/meeting-rooms-ii.html)
• Next Closest Time (https://leetfree.com/problems/next-closest-time.html)
• Replace Words (https://leetcode.com/problems/replace-words/description/)
• Happy Number (https://leetcode.com/problems/happy-number/)
• Bulls and Cows (https://leetcode.com/problems/bulls-and-cows/)
• Reverse Words in a String (https://leetcode.com/problems/reverse-words-in-a-string/)
• Number of Islands (https://leetcode.com/problems/number-of-islands/)
• Longest Substring Without Repeating Characters (https://leetcode.com/problems/longest-substring-without-repeating-characters/)
• Longest Substring Without Repeating Characters (https://leetcode.com/problems/longest-substring-without-repeating-characters/)
• Letter Combinations of a Phone Number (https://leetcode.com/problems/letter-combinations-of-a-phone-number)
• Kth Largest Element in an Array (https://leetcode.com/problems/kth-largest-element-in-an-array/)
• Kth Smallest Element in a Sorted Matrix (https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix/)
• 3Sum (https://leetcode.com/problems/3sum/)
• Girls and Boys Swap (no url)
• Permutations (https://leetcode.com/problems/permutations/)
• Permutations Exercise (for strings and integer lists)
• Fruit into Baskets (https://leetcode.com/problems/fruit-into-baskets/)
• 2nd Version using a dict
• Merge Intervals (https://leetcode.com/problems/merge-intervals/)
• Find First and Last Position of Element in Sorted Array (https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array)
• Is Subsequence (https://leetcode.com/problems/is-subsequence)
• Meeting Rooms II (https://leetcode.com/problems/meeting-rooms-ii/)
• Longest Palindromic Substring (https://leetcode.com/problems/longest-palindromic-substring/)
• Boats to Save People (https://leetcode.com/problems/boats-to-save-people/)
• Find Peak Element (https://leetcode.com/problems/find-peak-element/)
• Sort Characters by Frequency (https://leetcode.com/problems/sort-characters-by-frequency/)
• Generate Parentheses (https://leetcode.com/problems/generate-parentheses/)
• Top K Frequent Elements (https://leetcode.com/problems/top-k-frequent-elements/)
• Keys and Rooms (https://leetcode.com/problems/keys-and-rooms)
• K Closest Points to Origin (https://leetcode.com/problems/k-closest-points-to-origin/submissions/)
• Max Area of Island (https://leetcode.com/problems/max-area-of-island/)
• Game of Life (https://leetcode.com/problems/game-of-life/)
• Binary Tree Level Order Traversal (https://leetcode.com/problems/binary-tree-level-order-traversal)
• Summary Ranges (https://leetcode.com/problems/summary-ranges/)
• Subarray Sum Equals K (https://leetcode.com/problems/subarray-sum-equals-k/)
• Max Increase to Keep City Skyline (https://leetcode.com/problems/max-increase-to-keep-city-skyline/)
• Repeated DNA Sequences (https://leetcode.com/problems/repeated-dna-sequences/)
• Custom Sort String (https://leetcode.com/problems/custom-sort-string)
• Find Lonely Pixel (https://leetcode.com/problems/lonely-pixel-i/)
• Corporate Flight Bookings (https://leetcode.com/problems/corporate-flight-bookings)
• Top K Frequent Words (https://leetcode.com/problems/top-k-frequent-words/)
• Binary Tree Right Side View (https://leetcode.com/problems/binary-tree-right-side-view/)
• Minimum Add to Make Parentheses Valid (https://leetcode.com/problems/minimum-add-to-make-parentheses-valid)
• Maximum Binary Tree (https://leetcode.com/problems/maximum-binary-tree/)
• Minimum Moves to Equal Array Elements II (https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii/)
• 4Sum II (https://leetcode.com/problems/4sum-ii)
• Missing Element in Sorted Array (https://leetcode.com/problems/missing-element-in-sorted-array/)
• Design Circular Queue (https://leetcode.com/problems/design-circular-queue/)
• Path Sum II (https://leetcode.com/problems/path-sum-ii/)
• Symmetric Tree (https://leetcode.com/problems/symmetric-tree/)
• Find Largest Value in each Tree Row (https://leetcode.com/problems/find-largest-value-in-each-tree-row/submissions/)
• Maximum Level Sum of a Binary Tree (https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree/)
• Minimum Cost to Connect Sticks (https://leetcode.com/problems/minimum-cost-to-connect-sticks/)
• Single Number II (https://leetcode.com/problems/single-number-ii)
• Single Number III (https://leetcode.com/problems/single-number-iii/)
• Binary Search Tree to Greater Sum Tree (Binary Search Tree to Greater Sum Tree (https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree/)
• Find Bottom Left Tree Value (https://leetcode.com/problems/find-bottom-left-tree-value/)
• Reorganize String (https://leetcode.com/problems/reorganize-string/)
• Candy Crush (https://leetcode.com/problems/candy-crush)
• Before And After Puzzle (https://leetcode.com/problems/before-and-after-puzzle/)
• All Paths From Source to Target (https://leetcode.com/problems/all-paths-from-source-to-target/)
• Kill Process (https://leetcode.com/problems/kill-process/)
• Majority Element II (https://leetcode.com/problems/majority-element-ii/)
• Populating Next Right Pointers in Each Node (https://leetcode.com/problems/populating-next-right-pointers-in-each-node/)
• Populating Next Right Pointers in Each Node II (https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/)
• Flatten a Multilevel Doubly Linked List (https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list/)
• Campus Bikes (https://leetcode.com/problems/campus-bikes/)
• Car Pooling (https://leetcode.com/problems/car-pooling/)
• Find Smallest Common Element in All Rows (https://leetcode.com/problems/find-smallest-common-element-in-all-rows/)
• Teemo Attacking (https://leetcode.com/problems/teemo-attacking/)
• Reverse Substrings Between Each Pair of Parantheses (https://leetcode.com/problems/reverse-substrings-between-each-pair-of-parentheses/)
• Remove All Adjacent Duplicates in String II (https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii/)
• Time Based Key Value Store (https://leetcode.com/problems/time-based-key-value-store/)
• Design Hit Counter (https://leetcode.com/problems/design-hit-counter/)
• Two Sum BSTs (https://leetcode.com/problems/two-sum-bsts/)
• Insert Into a Binary Search Tree (https://leetcode.com/problems/insert-into-a-binary-search-tree/)
• Find All Duplicates in an Array (https://leetcode.com/problems/find-all-duplicates-in-an-array/)
• Find K-Length Substrings With No Repeated Characters (https://leetcode.com/problems/find-k-length-substrings-with-no-repeated-characters)
• Check if it is a Straight Line (https://leetcode.com/problems/check-if-it-is-a-straight-line/)
• Maximum Length of a String With Unique Characters (https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters/)
• Web Crawler (https://leetcode.com/problems/web-crawler/)
• Queens That Can Attack the King (https://leetcode.com/problems/queens-that-can-attack-the-king/)
• Design a Leaderboard (https://leetcode.com/problems/design-a-leaderboard/)
• Increasing Triplet Subsequence (https://leetcode.com/problems/increasing-triplet-subsequence/)
• Remove nth Node From End of List (https://leetcode.com/problems/remove-nth-node-from-end-of-list/)
• Odd Even Linked List (https://leetcode.com/problems/odd-even-linked-list)
• Word Search (https://leetcode.com/problems/word-search)
• Count Complete Tree Nodes (https://leetcode.com/problems/count-complete-tree-nodes)
• Minimum Domino Rotations for Equal Row (https://leetcode.com/problems/minimum-domino-rotations-for-equal-row/)
• Lowest Common Ancestor of a Binary Search Tree (https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/)
• Add Two Numbers (https://leetcode.com/problems/add-two-numbers/)
• Number of Closed Islands (https://leetcode.com/problems/number-of-closed-islands/)
• Sum Root to Leaf Numbers (https://leetcode.com/problems/sum-root-to-leaf-numbers/)
• Search in a Sorted Array of Unknown Size (https://leetcode.com/problems/search-in-a-sorted-array-of-unknown-size/)
• Linked List Cycle II (https://leetcode.com/problems/linked-list-cycle-ii/)
• Product of Array Except Self (https://leetcode.com/problems/product-of-array-except-self/)
• Sentence Similarity II (https://leetcode.com/problems/sentence-similarity-ii)
• Shortest Way to Form String (https://leetcode.com/problems/shortest-way-to-form-string/)
• Path With Maximum Gold (https://leetcode.com/problems/path-with-maximum-gold/)
• Deepest Leaves Sum (https://leetcode.com/problems/deepest-leaves-sum/)

Hard:

• Guess the Word (https://leetcode.com/problems/guess-the-word)
• Merge k Sorted Lists (https://leetcode.com/problems/merge-k-sorted-lists/)
• Serialize and Deserialize Binary Tree (https://leetcode.com/problems/serialize-and-deserialize-binary-tree/)
• Find Median from Data Stream (https://leetcode.com/problems/find-median-from-data-stream/)
• String Transforms Into Another String (https://leetcode.com/problems/string-transforms-into-another-string/)
• Word Break II (https://leetcode.com/problems/word-break-ii/description/)
• LRU Cache (https://leetcode.com/problems/lru-cache/)
• Longest Substring with At Most K Distinct Characters (https://leetfree.com/problems/longest-substring-with-at-most-k-distinct-characters.html)
• Candy (https://leetcode.com/problems/candy/)
• Median of Two Sorted Arrays (https://leetcode.com/problems/median-of-two-sorted-arrays/)
• Sliding Window Maximum (https://leetcode.com/problems/sliding-window-maximum/)
• Longest Substring with At Most Two Distinct Characters (https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/)
• Trapping Rain Water (https://leetcode.com/problems/trapping-rain-water/)
• Divide Chocolate (https://leetcode.com/problems/divide-chocolate/)