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Sorting Algorithms (2)
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Strings & Hashing Based Problems (26)
- Given a string, find if it has unique characters
- Reverse String
- Roman To Integer
- Integer To Roman
- Merge Strings Alternately
- Valid Anagram
- Group Anagrams
- Find All Anagrams in a String
- Find The Index of The First Occurrence in a String
- Is Subsequence
- Length Of Last Word
- Longest Common Prefix
- Isomorphic Strings
- Maximum Number of Balloons
- Word Pattern
- Encode and Decode Strings
- Encode and Decode Tiny URL
- Unique Length-3 Palindromic Subsequences
- Minimum Number of Swaps to Make The String Balanced
- Maximum Product of The Length of Two Palindromic Subsequences
- Repeated DNA Sequences
- Check if a String Contains all Binary Codes of Size K
- Optimal Partition of String
- Basic Calculator II
- Valid Palindrome
- Valid Palindrome II
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Arrays & Hashing Based Problems (60)
- Two Sum - Find a pair of integers from an array whose sum equal to a target K
- Two Sum II, Input Array Is Sorted
- 3 Sum - Find all triplets from array whose sum equal to 0
- 4 Sum - Find all quadruplets from array whose sum equal to a target N
- Transpose Matrix
- Design HashSet
- Design HashMap
- Contains Duplicates
- Concatenation of Array
- Replace elements with greatest element on right side
- Pascal's Triangle
- Remove Element
- Unique Email Addresses
- Can Place Flowers
- Majority Element
- Next Greater Element
- Find Pivot Index
- Range Sum Query Immutable
- Range Sum Query 2D Immutable
- Find All Numbers Disappeared in an Array
- Find Kth largest element in an unsorted array
- Top K Frequent Elements
- Product of Array Except Self
- Valid Sudoku
- Longest Consecutive Sequence
- Sort Colors
- Squares of a Sorted Array
- Brick Wall
- Best Time to Buy and Sell Stock II
- Subarray Sum Equals K
- Number of Pairs of Interchangeable Rectangles
- Grid Game
- Wiggle Sort
- Largest Number
- Continuous Subarray Sum
- Push Dominoes
- Insert Delete Get Random O(1)
- Non Decreasing Array
- First Missing Positive
- Sign of An Array
- Find the Difference of Two Arrays
- Design Parking System
- Number of Zero-Filled Subarrays
- Design Underground System
- Minimum Penalty for a Shop
- Text Justification
- Naming a Company
- Minimum Difference Between Highest and Lowest of K Scores
- Merge Sorted Array
- Move Zeroes
- Container With Most Water
- Remove Duplicates From Sorted Array
- Remove Duplicates From Sorted Array II
- Number of Subsequences That Satisfy the Given Sum Condition
- Rotate Array
- Array With Elements Not Equal to Average of Neighbors
- Boats to Save People
- Trapping Rain Water
- Median of two sorted arrays of same size
- Median of two sorted arrays of different size
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Dynamic Programming Based Problems (13)
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Graph Based Problems (1)
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Sliding Window Based Problems (17)
- Best Time to Buy and Sell Stock
- Contains Duplicate II
- Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold
- Longest Substring Without Repeating Characters
- Longest Repeating Character Replacement
- Permutation in String
- Frequency of the Most Frequent Element
- Fruits Into Basket
- Maximum Number of Vowels in a Substring of Given Length
- Minimum Number of Flips to Make the Binary String Alternating
- Minimum Size Subarray Sum
- Find K Closest Elements
- Minimum Operations to Reduce X to Zero
- Minimum Window Substring
- Sliding Window Maximum
- Longest substring with K unique characters
- Longest Substring with At Least K Repeating Characters
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Stack Based Problems (18)
- Valid Parentheses
- Baseball Game
- Implement Stack Using Queues
- Min Stack
- Evaluate Reverse Polish Notation
- Removing Stars From a String
- Validate Stack Sequences
- Asteroid Collision
- Daily Temperatures
- Online Stock Span
- Car Fleet
- Simplify Path
- Decode String
- Remove K Digits
- Remove All Adjacent Duplicates In String II
- 132 Pattern
- Maximum Frequency Stack
- Largest Rectangle In Histogram
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Linked List Based Problems (2)
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Backtracking Based Problems (1)