15 Core Greedy Patterns for Coding Interviews

Hey guyss! Be greedy to read this post.
The goal of this post is simple: bring together the most important greedy patterns in one place, with practice problems under each so that you can learn them the right way. If you go through these patterns one by one, you’ll notice that almost every greedy question you see in interviews fits neatly into one of them.

15 Greedy Patterns for Coding Interviews

Greedy algorithms look simple, but the real challenge is recognizing when they actually work.
Most students get confused because greedy problems come in many forms — intervals, sorting, tasks, graphs, heaps, arrays, strings — all looking unrelated.

But here’s the truth: Greedy problems follow a set of consistent patterns.
Once you master these patterns, you’ll instantly recognize them in interviews and solve them with confidence.

Below are the 15 essential Greedy Patterns you must know, along with
Practice Problems + Bonus Problems for each.

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Pattern 1: Interval Scheduling

Sorting intervals by start/end and picking non-overlapping ones.

Practice Problems:

• Non-overlapping Intervals
• Merge Intervals
• Meeting Rooms II
• Minimum Number of Arrows to Burst Balloons
• Insert Interval

Bonus Problems:

• Meeting Rooms
• Interval List Intersections

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Pattern 2: Fractional Knapsack

Pick items based on best value/weight ratio.

Practice Problems:

• Assign Cookies
• Candy
• Gas Station
• Minimum Number of Refueling Stops
• Minimized Maximum of Products Distributed to Any Store

Bonus Problems:

• Maximum Ice Cream Bars
• Largest Values After K Operations

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Pattern 3: Job Sequencing / Deadline Scheduling

Pick jobs by deadlines or profits.

Practice Problems:

• Course Schedule III
• Task Scheduler
• IPO
• Two City Scheduling
• Minimum Number of Refueling Stops

Bonus Problems:

• Last Moment Before All Ants Fall Out
• Earliest Possible Day of Full Bloom

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Pattern 4: Frequency Merging / Huffman-Type Greedy

Repeatedly combining items with smallest cost using a heap.

Practice Problems:

• Minimum Cost to Connect Sticks
• Reorganize String
• Sort Characters By Frequency
• Reduce Array Size to the Half
• Divide Array in Sets of K Consecutive Numbers

Bonus Problems:

• Top K Frequent Elements
• Least Number of Unique Integers After K Removals

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Pattern 5: Coin Change (Greedy Variant)

Works only for canonical coin systems.

Practice Problems:

• Lemonade Change
• Minimum Moves to Reach Target With Rotations
• Count Operations to Obtain Zero
• Minimum Operations to Make Array Equal
• Minimum Deletions to Make Character Frequencies Unique

Bonus Problems:

• Minimum Cost to Move Chips to the Same Position
• Minimum Elements to Add to Form a Given Sum

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Pattern 6: Sorting + Greedy Decision

Sort → apply greedy for optimal pairing/allocation.

Practice Problems:

• Queue Reconstruction by Height
• Boats to Save People
• Two City Scheduling
• Car Pooling
• Maximum Units on a Truck

Bonus Problems:

• Minimum Absolute Difference
• Reduce File Size

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Pattern 7: Prefix/Suffix Greedy

Optimize based on prefix/suffix choices.

Practice Problems:

• Jump Game
• Jump Game II
• Maximum Subarray
• Minimum Deletions to Make String Balanced
• Partition Labels

Bonus Problems:

• Maximum Sum Circular Subarray
• Shortest Way to Form String

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Pattern 8: Priority Queue Greedy

Repeated greedy choice from dynamic set.

Practice Problems:

• Task Scheduler
• Reorganize String
• IPO
• Hand of Straights
• Least Interval

Bonus Problems:

• Seat Reservation Manager
• Maximum Subsequence Score

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Pattern 9: Greedy in Graph Algorithms

Greedy inside MST / shortest path logic.

Practice Problems:

• Network Delay Time
• Path With Minimum Effort
• Swim in Rising Water
• Minimum Cost to Connect All Points
• Cheapest Flights Within K Stops

Bonus Problems:

• Find Critical and Pseudo-Critical Edges
• Kruskal-like MST Variation

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Pattern 10: Exchange Argument / Proof-Based Greedy

Used when greedy is not obvious.

Practice Problems:

• Jump Game
• Gas Station
• Candy
• Maximum Subarray
• Longest Happy String

Bonus Problems:

• Split Array Into Consecutive Subsequences
• Remove Duplicate Letters

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Pattern 11: Greedy Digit / Number Construction

Choosing digits/values step-by-step.

Practice Problems:

• Remove K Digits
• Monotone Increasing Digits
• Smallest Number at Given Digit Swaps
• Maximum Swap
• Next Greater Element III

Bonus Problems:

• Largest Number
• Sum of Digits of String After Convert

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Pattern 12: Greedy String Construction

Pick best local character choice.

Practice Problems:

• Remove Duplicate Letters
• Smallest Subsequence of Distinct Characters
• Orderly Queue
• Lexicographically Smallest Equivalent String
• Longest Happy String

Bonus Problems:

• Break a Palindrome
• Make String a Subsequence Using Cyclic Increments

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Pattern 13: Optimal Partitioning

Divide array/string into optimal segments.

Practice Problems:

• Partition Labels
• String Compression II (has greedy inside)
• Minimum Length of String After Deleting Similar Ends
• Minimum Operations to Make the Array K-Increasing
• Split Array Largest Sum

Bonus Problems:

• Longest Chunked Palindrome Decomposition
• Minimum Number of Refueling Stops

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Pattern 14: Greedy Based on Parity / Contribution

Choose based on contribution to final score.

Practice Problems:

• Maximize Sum of Array After K Negations
• Minimize Maximum Pair Sum in Array
• Maximum Score From Removing Stones
• Minimum Operations to Halve Array Sum
• Minimize Sum of Distances in Array

Bonus Problems:

• Maximum Number of Coins You Can Get
• Minimum Increment to Make Array Unique

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Pattern 15: Greedy Selection With Constraints

Pick best option allowed by constraints (capacity, balance, conditions).

Practice Problems:

• Maximum Score From Performing Multiplication Operations
• Jump Game VI
• Maximum Bags With Full Capacity of Rocks
• Split a String Into the Max Number of Unique Substrings
• Longest Happy Prefix

Bonus Problems:

• Minimum Cost to Make at Least One Valid Path in a Grid
• Maximum Alternating Subsequence Sum

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Would love to indulge your patterns, Qns and add-ons, do share your thoughts!
If you found this post useful please upvote.
Happy Coding!!

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