Browse by Pattern

Master coding patterns with 28 different algorithmic approaches

Array

6 problems
Fundamental data structure problems involving indexing, iteration, and manipulation.
Two Sum Easy
Contains Duplicate Easy
and 4 more...
Time: O(n)
Space: O(n), O(1)
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Two Pointers

5 problems
Use two pointers moving towards each other or in the same direction to solve in O(n) time.
Find First and Last Position Medium
Valid Palindrome Easy
and 3 more...
Time: O(log n), O(n)
Space: O(1)
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Dynamic Programming

4 problems
Break problems into subproblems and memoize results to avoid redundant computation.
Climbing Stairs Easy
House Robber Medium
and 2 more...
Time: O(n), O(amount × coins), O(n²)
Space: O(1), O(amount), O(n)
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Hash Map

4 problems
Use hash tables for O(1) lookups and frequency counting. Great for key-value relationships.
Two Sum Easy
Group Anagrams Medium
and 2 more...
Time: O(n), O(n * k log k), O(n log n)
Space: O(n), O(n * k), O(k)
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DFS

3 problems
Depth-first search for exploring all paths in trees and graphs recursively.
Maximum Depth of Binary Tree Easy
Same Tree Easy
and 1 more...
Time: O(n), O(V + E)
Space: O(h), O(V)
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Sorting

3 problems
Arrange elements in order using various sorting algorithms and techniques.
Group Anagrams Medium
Top K Frequent Elements Medium
and 1 more...
Time: O(n * k log k), O(n log n)
Space: O(n * k), O(n)
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Tree

3 problems
Hierarchical data structure problems involving traversal, construction, and manipulation.
Maximum Depth of Binary Tree Easy
Same Tree Easy
and 1 more...
Time: O(n)
Space: O(h), O(n)
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BFS

2 problems
Breadth-first search for shortest path and level-order traversal problems.
Binary Tree Level Order Traversal Medium
Shortest Path in Unweighted Graph Medium
Time: O(n), O(V + E)
Space: O(n), O(V)
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Binary Search

2 problems
Divide and conquer on sorted data to achieve O(log n) search complexity.
Binary Search Easy
Find First and Last Position Medium
Time: O(log n)
Space: O(1)
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Graph

2 problems
Problems involving vertices, edges, and relationships between entities.
Number of Connected Components Medium
Shortest Path in Unweighted Graph Medium
Time: O(V + E)
Space: O(V)
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Greedy

2 problems
Make locally optimal choices hoping to find a global optimum.
Best Time to Buy and Sell Stock Easy
Payroll Distribution Hard
Time: O(n), O(n log n)
Space: O(1), O(n)
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Recursion

2 problems
Solve problems by breaking them down into smaller instances of the same problem.
Maximum Depth of Binary Tree Easy
Same Tree Easy
Time: O(n)
Space: O(h)
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Stack

2 problems
LIFO data structure for parsing, expression evaluation, and nested structure problems.
Valid Parentheses Easy
Daily Temperatures Medium
Time: O(n)
Space: O(n)
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String

2 problems
Text processing, pattern matching, and character manipulation problems.
Group Anagrams Medium
Valid Palindrome Easy
Time: O(n * k log k), O(n)
Space: O(n * k), O(1)
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Divide and Conquer

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Merge Sort Medium
Time: O(n log n)
Space: O(n)
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Fibonacci

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Climbing Stairs Easy
Time: O(n)
Space: O(1)
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Hash Set

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Contains Duplicate Easy
Time: O(n)
Space: O(n)
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Heap

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Top K Frequent Elements Medium
Time: O(n log n)
Space: O(n)
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Knapsack

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Coin Change Medium
Time: O(amount × coins)
Space: O(amount)
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LIS

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Longest Increasing Subsequence Hard
Time: O(n²)
Space: O(n)
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Math

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Payroll Distribution Hard
Time: O(n log n)
Space: O(n)
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Monotonic Stack

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Daily Temperatures Medium
Time: O(n)
Space: O(n)
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Prefix Sum

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Product of Array Except Self Medium
Time: O(n)
Space: O(1)
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Proportional Allocation

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Payroll Distribution Hard
Time: O(n log n)
Space: O(n)
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Queue

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Binary Tree Level Order Traversal Medium
Time: O(n)
Space: O(n)
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Shortest Path

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Shortest Path in Unweighted Graph Medium
Time: O(V + E)
Space: O(V)
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Sliding Window

1 problem
Maintain a window of elements and slide it to find optimal subarrays efficiently.
Longest Substring Without Repeating Characters Medium
Time: O(n)
Space: O(k)
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Union Find

1 problem
A useful algorithmic pattern for solving coding problems efficiently.
Number of Connected Components Medium
Time: O(V + E)
Space: O(V)
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Pattern Statistics

28
Total Patterns
6
Most Used Pattern
2.2
Avg Patterns/Problem
7
Core Patterns (3+)

Most Popular Patterns

Array 6 Two Pointers 5 Dynamic Programming 4 Hash Map 4 DFS 3 Sorting 3 Tree 3 BFS 2 Binary Search 2 Graph 2
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