
Learn six common coding patterns for interviews, including two pointers, sliding window, merge intervals, k merge, and in-place reversal, with guidance on when to use each.
Leetcode 56
This problem has been asked at [ Amazon, Bloomberg, Meta ]
This problem has been asked at [ Amazon, Apple, Adobe]
This problem has been asked at [ Amazon, Apple, Adobe]
This problem has been asked at [ Amazon, Apple, Adobe]
This problem has been asked at [ Amazon, Apple, Adobe]
This problem has been asked at [ Amazon, Apple, Google]
Learn to flip an image represented as a matrix horizontally and invert it in place. Use a reverse step to flip and xor with one to invert zeros and ones.
Apply a pass to minimize switches and turn all bulbs on: flip a zero, which also flips the bulbs to the right, using even or odd cost to guide flips.
Sort intervals by end time. Greedily select disjoint intervals to maximize the count, illustrated with examples and coding steps.
This problem has been asked at [ Amazon, Bloomberg, Google]
This problem has been asked at [ Amazon, Bloomberg, Google]
This problem has been asked at [ Amazon, Bloomberg, TikTok]
This problem has been asked at [ Amazon, Bloomberg, TikTok]
This problem has been asked at [ Asked at Amazon , Apple , Twitter]
This problem has been asked at [ Asked at Amazon , Apple , Twitter]
Explore core graph concepts, including directed and undirected graphs, weights, cycles, in-degree and out-degree, and representations with adjacency matrices and lists; learn DFS, BFS, and topological sort with Kahn's algorithm.
Apply Kahn's algorithm to perform a topological sort by identifying in-degree zero nodes, removing outgoing edges, and building the output order step by step.
Learn to implement topological sort with breadth-first search using a queue, graph and in-degree mapping to solve course schedule and alien dictionary problems with the same approach.
apply topological sort via breadth-first search to determine if all courses can be finished given prerequisites; detect cycles, with edges representing prerequisites and examples showing true or false outcomes.
Learn how to solve course scheduling with topological sort in Python, using a graph and in-degree, a queue, and a finished-courses tracker to verify all prerequisites.
Explore depth-first search on trees, including root, leaves, and left and right children, and learn the leftmost path traversal. Master the preorder, inorder, and postorder traversals.
Explore solving the target sum problem on a tree by subtracting node values from the target along a root-to-leaf path and backtracking until a leaf yields zero.
Covers around 20+ most popular coding interview problems ranging from a variety of topics ( will have 200+ problems as 4 problems are being added every week)
Merge Intervals
Idea of Merge Intervals
Merge Intervals
Intervals Intersection (coming soon)
Conflicting Appointments (coming soon)
Two Pointers
Idea of Two pointers and types of two pointers solutions
Two Sum
Remove Duplicates from Sorted Array
3 Sum
Pair with Target Sum (coming soon)
Squaring a Sorted Array (coming soon)
Triplet Sum to Zero (coming soon)
Triplet Sum Close to Target (coming soon)
Triplets with Smaller Sum (coming soon)
Subarrays with Product Less than a Target (coming soon)
Dutch National Flag Problem (coming soon)
Fast & Slow Pointers
Linked List Cycle using Floyd's Cycle Detection Algorithm
Happy Numbers
Ugly number (coming soon)
Middle of the LinkedList (coming soon)
LinkedList Cycle (coming soon)
Start of LinkedList Cycle (coming soon)
Bitwise Manipulation
Single Numbers
Flipping an Image
Single Number II ( coming soon)
Single Number III ( coming soon)
Greedy Technique
What are Greedy Algorithms ?
Bulbs
Highest Product
Disjoint Sets
Largest Permutation ( coming soon)
Meeting rooms ( coming soon)
Distribute Candy ( coming soon)
Seats ( coming soon)
Assign Mice to Holes ( coming soon)
Majority Element ( coming soon)
Gas Station ( coming soon)
Island Patterns
Intro to Matrix
Number of Islands Explanation
Number of Islands Code
Number of distinct Islands Explanation
Number of distinct island coding
Count sub islands
Max Area of an island (coming soon)
Island Perimeter (coming soon)
Flood fill (coming soon)
Wall and Fates (coming soon)
Minesweeper (coming soon)
Surrounded Regions (coming soon)
Find all groups of a farm land (coming soon)
Topological Sort
Introduction to Graph Problems
Topological Sort
Kahn's Algorithm
Implementing Topological Sort
Course Schedule
Alien Dictionary
Minimum Height Trees (coming soon)
All Ancestors of a Node in a Directed Acyclic Graph (coming soon)
Build a Matrix With Conditions (coming soon)
Find All Possible Recipes from Given Supplies (coming soon)
Depth First Search
Path Sum
Upcoming Additions (3-4 problems are added every week)
Sliding Window
Easy
Maximum Sum Subarray of Size K
Smallest Subarray With a Greater Sum
Medium
Longest Substring with maximum K Distinct Characters
Fruits into Baskets
Hard
Longest Substring with Distinct Characters
Longest Substring with Same Letters after Replacement
Longest Subarray with Ones after Replacement
Arrays
Medium
Group Anagrams
Hard
Trapping Rain Water
Merge Intervals
Medium
Intervals Intersection
Conflicting Appointments
Linked List
Easy
Reverse a Linked List
Medium
Reverse a sub list
Reverse a k-element sub list
Two Heaps
Medium
Find the median of a number stream
Hard
Maximum Capital
Sliding Window Median
Top k elements
Easy
Top 'K' Numbers
Kth Smallest Number
'K' Closest Points to the Origin
Connect Ropes
Medium
Top 'K' Frequent Numbers
Frequency Sort
Kth Largest Number in a Stream
'K' Closest Numbers
Maximum Distinct Elements
Sum of Elements
Hard
Rearrange String
K-way merge
Binary Search
Backtracking
1D Dynamic programing
2D Dynamic programing
Cyclic Sort
Topological Sort
Stacks
Queues
Depth First Search
Breadth First Search
Trie
Hash Maps
Math Tricks
Miscellaneous