Pattern 15 of 22

Greedy Pattern: Template + 346 LeetCode Problems

Take the locally best option every time — when you can prove that never costs you later.

Easy: 41
Medium: 234
Hard: 71

What the greedy pattern is

A greedy algorithm commits to the best-looking option at each step and never reconsiders, which makes it the fastest thing that can possibly work and also the easiest thing to get silently wrong. The hard part is never the code — it is three lines — but the justification, and the tool for that is the exchange argument: assume an optimal solution differs from the greedy one, look at the first place they diverge, and show that swapping in the greedy choice leaves the solution no worse. If that swap holds, greedy is correct; if it does not, the problem is dynamic programming wearing a disguise. Choosing what to be greedy about is usually a sorting decision, and the sort key is where the insight lives: interval scheduling works when you sort by earliest finishing time, because finishing early leaves the maximum room for everything after, and it quietly fails if you sort by start time or by duration instead.

When to use it

A local choice can be shown, by an exchange argument, never to rule out an optimal completion.
Sorting the input by one well-chosen key makes the right choice obvious at every step.
The problem is interval scheduling, jump reachability, or an assignment with a clear ordering.
A dynamic programming solution exists but its state collapses to a single running best.

The greedy template in Python

The shape, not a solution to any one problem. Adapt the condition and the summary being maintained; the skeleton stays the same across the 346 problems listed below.

PythonGreedy template

def max_non_overlapping(intervals):
    intervals.sort(key=lambda pair: pair[1])   # earliest finishing time first
    last_end = float("-inf")
    kept = 0

    for start, finish in intervals:
        if start >= last_end:      # taking it never blocks a better option later
            kept += 1
            last_end = finish

    return kept

Complexity characteristics

Time: O(n log n)dominated by the sort
Auxiliary space: O(1) to O(n)

The greedy pass itself is a single linear scan; the sort that makes the greedy choice correct is what sets the complexity. When no sort is needed — a running maximum, a reachability check — the whole solution is O(n). The space is the sort's, which in Python means O(n) for Timsort's temporary buffer rather than the O(1) an in-place quicksort would suggest.

Eyes only

Meet the greedy problem you did not practise.

In the live round, Stealth Interview reads the problem off your screen, returns a working solution with a step-by-step explanation and its time and space complexity, and transcribes what the interviewer says. It's a desktop app for macOS and Windows, invisible to screen sharing.

Get Stealth Interview See pricing

90%Subscription

python

Please analyze this context and help me answer the question or solve the problem.

Technical interview · 45 minsolution.pyShared editor · Python 3Longest substring without repeatsMediumGiven a string s, return the length of the longest contiguous substring in which every character is unique.s = "abcabcbb"
→ 31def length_of_longest_substring(s: str) -> int:2 last_seen = {}3 left = best = 04 for right, ch in enumerate(s):5 if ch in last_seen and last_seen[ch] >= left:

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 Terra

90%Subscription

python

Please analyze this context and help me answer the question or solve the problem.

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 TerraClear chat

QuitEscHide+QCapture+PCrop+OSubmit+EnterPress to get answerLeft/Right+Up/Down+

90%Subscription

python

Please analyze this context and help me answer the question or solve the problem.

python

def length_of_longest_substring(s: str) -> int:    last_seen = {}                    # char -> index    left = best = 0    for right, ch in enumerate(s):        if ch in last_seen and last_seen[ch] >= left:            left = last_seen[ch] + 1  # jump past it        last_seen[ch] = right        best = max(best, right - left + 1)    return best    last_seen = {}                    # char -> index

Approach

At each index r, the window's left edge is:

left r = max (left r -1, last[s r] + 1)

Time O(n): each character enters and leaves the window once.
Space O(min(n, k)): k is the size of the character set.

Type your message...

GPT-6.1 TerraClear chat

Primary display

QuitEscHide+QCapture+PCrop+OSubmit+EnterPress to get answerLeft/Right+Up/Down+

All 346 greedy LeetCode problems

Every problem in the library the greedy pattern applies to, grouped by LeetCode's own difficulty rating. 308 of the 346 carry a complete Python solution with a worked example and complexity analysis; the rest are listed for completeness, with the LeetCode Premium ones marked.

Easy (41)

Easy problems
No.	Problem	Topics
0409	Longest Palindrome	Greedy, Hash Table, String
0455	Assign Cookies	Greedy, Array, Two Pointers +1
0561	Array Partition	Greedy, Array, Counting Sort +1
0605	Can Place Flowers	Greedy, Array
0680	Valid Palindrome II	Greedy, Two Pointers, String
0860	Lemonade Change	Greedy, Array
0942	DI String Match	Greedy, Array, Two Pointers +1
0976	Largest Perimeter Triangle	Greedy, Array, Math +1
1005	Maximize Sum Of Array After K Negations	Greedy, Array, Sorting
1013	Partition Array Into Three Parts With Equal Sum	Greedy, Array
1196	How Many Apples Can You Put into the BasketPremium	Greedy, Array, Sorting
1217	Minimum Cost to Move Chips to The Same Position	Greedy, Array, Math
1221	Split a String in Balanced Strings	Greedy, String, Counting
1323	Maximum 69 Number	Greedy, Math
1403	Minimum Subsequence in Non-Increasing Order	Greedy, Array, Sorting
1708	Largest Subarray Length KPremium	Greedy, Array
1710	Maximum Units on a Truck	Greedy, Array, Sorting
1736	Latest Time by Replacing Hidden Digits	Greedy, String
1827	Minimum Operations to Make the Array Increasing	Greedy, Array
1903	Largest Odd Number in String	Greedy, Math, String
1974	Minimum Time to Type Word Using Special Typewriter	Greedy, String
2027	Minimum Moves to Convert String	Greedy, String
2037	Minimum Number of Moves to Seat Everyone	Greedy, Array, Counting Sort +1
2078	Two Furthest Houses With Different Colors	Greedy, Array
2144	Minimum Cost of Buying Candies With Discount	Greedy, Array, Sorting
2160	Minimum Sum of Four Digit Number After Splitting Digits	Greedy, Math, Sorting
2224	Minimum Number of Operations to Convert Time	Greedy, String
2259	Remove Digit From Number to Maximize Result	Greedy, String, Enumeration
2335	Minimum Amount of Time to Fill Cups	Greedy, Array, Sorting +1
2357	Make Array Zero by Subtracting Equal Amounts	Greedy, Array, Hash Table +3
2383	Minimum Hours of Training to Win a Competition	Greedy, Array
2389	Longest Subsequence With Limited Sum	Greedy, Array, Binary Search +2
2566	Maximum Difference by Remapping a Digit	Greedy, Math
2578	Split With Minimum Sum	Greedy, Math, Sorting
2591	Distribute Money to Maximum Children	Greedy, Math
2600	K Items With the Maximum Sum	Greedy, Math
2656	Maximum Sum With Exactly K Elements	Greedy, Array
2697	Lexicographically Smallest Palindrome	Greedy, Two Pointers, String
2706	Buy Two Chocolates	Greedy, Array, Sorting
2864	Maximum Odd Binary Number	Greedy, Math, String
2900	Longest Unequal Adjacent Groups Subsequence I	Greedy, Array, String +1

Medium (234)

Medium problems
No.	Problem	Topics
0011	Container With Most Water	Greedy, Array, Two Pointers
0045	Jump Game II	Greedy, Array, Dynamic Programming
0055	Jump Game	Greedy, Array, Dynamic Programming
0122	Best Time to Buy and Sell Stock II	Greedy, Array, Dynamic Programming
0134	Gas Station	Greedy, Array
0179	Largest Number	Greedy, Array, String +1
0316	Remove Duplicate Letters	Stack, Greedy, String +1
0324	Wiggle Sort II	Greedy, Array, Divide and Conquer +2
0334	Increasing Triplet Subsequence	Greedy, Array
0376	Wiggle Subsequence	Greedy, Array, Dynamic Programming
0397	Integer Replacement	Greedy, Bit Manipulation, Memoization +1
0402	Remove K Digits	Stack, Greedy, String +1
0435	Non-overlapping Intervals	Greedy, Array, Dynamic Programming +1
0452	Minimum Number of Arrows to Burst Balloons	Greedy, Array, Sorting
0581	Shortest Unsorted Continuous Subarray	Stack, Greedy, Array +3
0611	Valid Triangle Number	Greedy, Array, Two Pointers +2
0621	Task Scheduler	Greedy, Array, Hash Table +3
0624	Maximum Distance in Arrays	Greedy, Array
0646	Maximum Length of Pair Chain	Greedy, Array, Dynamic Programming +1
0649	Dota2 Senate	Greedy, Queue, String
0659	Split Array into Consecutive Subsequences	Greedy, Array, Hash Table +1
0670	Maximum Swap	Greedy, Math
0678	Valid Parenthesis String	Stack, Greedy, String +1
0714	Best Time to Buy and Sell Stock with Transaction Fee	Greedy, Array, Dynamic Programming
0738	Monotone Increasing Digits	Greedy, Math
0763	Partition Labels	Greedy, Hash Table, Two Pointers +1
0846	Hand of Straights	Greedy, Array, Hash Table +1
1899	Merge Triplets to Form Target Triplet	Greedy, Array
2542	Maximum Subsequence Score	Greedy, Array, Sorting +1
0253	Meeting Rooms IIPremium	Greedy, Array, Two Pointers +3
0280	Wiggle SortPremium	Greedy, Array, Sorting
0484	Find PermutationPremium	Stack, Greedy, Array +1
0555	Split Concatenated StringsPremium	Greedy, Array, String
0625	Minimum FactorizationPremium	Greedy, Math
0767	Reorganize String	Greedy, Hash Table, String +3
0769	Max Chunks To Make Sorted	Stack, Greedy, Array +2
0781	Rabbits in Forest	Greedy, Array, Hash Table +1
0807	Max Increase to Keep City Skyline	Greedy, Array, Matrix
0826	Most Profit Assigning Work	Greedy, Array, Two Pointers +2
0861	Score After Flipping Matrix	Greedy, Bit Manipulation, Array +1
0870	Advantage Shuffle	Greedy, Array, Two Pointers +1
0881	Boats to Save People	Greedy, Array, Two Pointers +1
0910	Smallest Range II	Greedy, Array, Math +1
0921	Minimum Add to Make Parentheses Valid	Stack, Greedy, String
0945	Minimum Increment to Make Array Unique	Greedy, Array, Counting +1
0948	Bag of Tokens	Greedy, Array, Two Pointers +1
0954	Array of Doubled Pairs	Greedy, Array, Hash Table +1
0955	Delete Columns to Make Sorted II	Greedy, Array, String
0969	Pancake Sorting	Greedy, Array, Two Pointers +1
0984	String Without AAA or BBB	Greedy, String
0991	Broken Calculator	Greedy, Math
1007	Minimum Domino Rotations For Equal Row	Greedy, Array
1024	Video Stitching	Greedy, Array, Dynamic Programming
1029	Two City Scheduling	Greedy, Array, Sorting
1053	Previous Permutation With One Swap	Greedy, Array
1054	Distant Barcodes	Greedy, Array, Hash Table +3
1055	Shortest Way to Form StringPremium	Greedy, Two Pointers, String +1
1058	Minimize Rounding Error to Meet TargetPremium	Greedy, Array, Math +2
1081	Smallest Subsequence of Distinct Characters	Stack, Greedy, String +1
1090	Largest Values From Labels	Greedy, Array, Hash Table +2
1130	Minimum Cost Tree From Leaf Values	Stack, Greedy, Array +2
1144	Decrease Elements To Make Array Zigzag	Greedy, Array
1167	Minimum Cost to Connect SticksPremium	Greedy, Array, Heap (Priority Queue)
1247	Minimum Swaps to Make Strings Equal	Greedy, Math, String
1253	Reconstruct a 2-Row Binary Matrix	Greedy, Array, Matrix
1262	Greatest Sum Divisible by Three	Greedy, Array, Dynamic Programming +1
1282	Group the People Given the Group Size They Belong To	Greedy, Array, Hash Table
1296	Divide Array in Sets of K Consecutive Numbers	Greedy, Array, Hash Table +1
1328	Break a Palindrome	Greedy, String
1338	Reduce Array Size to The Half	Greedy, Array, Hash Table +2
1353	Maximum Number of Events That Can Be Attended	Greedy, Array, Sorting +1
1382	Balance a Binary Search Tree	Greedy, Tree, Depth-First Search +3
1386	Cinema Seat Allocation	Greedy, Bit Manipulation, Array +1
1400	Construct K Palindrome Strings	Greedy, Hash Table, String +1
1405	Longest Happy String	Greedy, String, Heap (Priority Queue)
1414	Find the Minimum Number of Fibonacci Numbers Whose Sum Is K	Greedy, Math
1432	Max Difference You Can Get From Changing an Integer	Greedy, Math
1433	Check If a String Can Break Another String	Greedy, String, Sorting
1465	Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts	Greedy, Array, Sorting
1481	Least Number of Unique Integers after K Removals	Greedy, Array, Hash Table +2
1488	Avoid Flood in The City	Greedy, Array, Hash Table +2
1509	Minimum Difference Between Largest and Smallest Value in Three Moves	Greedy, Array, Sorting
1529	Minimum Suffix Flips	Greedy, String
1536	Minimum Swaps to Arrange a Binary Grid	Greedy, Array, Matrix
1541	Minimum Insertions to Balance a Parentheses String	Stack, Greedy, String
1546	Maximum Number of Non-Overlapping Subarrays With Sum Equals Target	Greedy, Array, Hash Table +1
1558	Minimum Numbers of Function Calls to Make Target Array	Greedy, Bit Manipulation, Array
1561	Maximum Number of Coins You Can Get	Greedy, Array, Math +2
1564	Put Boxes Into the Warehouse IPremium	Greedy, Array, Sorting
1567	Maximum Length of Subarray With Positive Product	Greedy, Array, Dynamic Programming
1578	Minimum Time to Make Rope Colorful	Greedy, Array, String +1
1580	Put Boxes Into the Warehouse IIPremium	Greedy, Array, Sorting
1589	Maximum Sum Obtained of Any Permutation	Greedy, Array, Prefix Sum +1
1605	Find Valid Matrix Given Row and Column Sums	Greedy, Array, Matrix
1642	Furthest Building You Can Reach	Greedy, Array, Heap (Priority Queue)
1647	Minimum Deletions to Make Character Frequencies Unique	Greedy, Hash Table, String +1
1648	Sell Diminishing-Valued Colored Balls	Greedy, Array, Math +3
1663	Smallest String With A Given Numeric Value	Greedy, String
1673	Find the Most Competitive Subsequence	Stack, Greedy, Array +1
1686	Stone Game VI	Greedy, Array, Math +3
1689	Partitioning Into Minimum Number Of Deci-Binary Numbers	Greedy, String
1702	Maximum Binary String After Change	Greedy, String
1705	Maximum Number of Eaten Apples	Greedy, Array, Heap (Priority Queue)
1717	Maximum Score From Removing Substrings	Stack, Greedy, String
1727	Largest Submatrix With Rearrangements	Greedy, Array, Matrix +1
1733	Minimum Number of People to Teach	Greedy, Array, Hash Table
1753	Maximum Score From Removing Stones	Greedy, Math, Heap (Priority Queue)
1754	Largest Merge Of Two Strings	Greedy, Two Pointers, String
1764	Form Array by Concatenating Subarrays of Another Array	Greedy, Array, Two Pointers +1
1775	Equal Sum Arrays With Minimum Number of Operations	Greedy, Array, Hash Table +1
1785	Minimum Elements to Add to Form a Given Sum	Greedy, Array
1792	Maximum Average Pass Ratio	Greedy, Array, Heap (Priority Queue)
1794	Count Pairs of Equal Substrings With Minimum DifferencePremium	Greedy, Hash Table, String
1798	Maximum Number of Consecutive Values You Can Make	Greedy, Array, Sorting
1802	Maximum Value at a Given Index in a Bounded Array	Greedy, Math, Binary Search
1824	Minimum Sideway Jumps	Greedy, Array, Dynamic Programming
1833	Maximum Ice Cream Bars	Greedy, Array, Counting Sort +1
1838	Frequency of the Most Frequent Element	Greedy, Array, Binary Search +3
1846	Maximum Element After Decreasing and Rearranging	Greedy, Array, Sorting
1850	Minimum Adjacent Swaps to Reach the Kth Smallest Number	Greedy, Two Pointers, String
1864	Minimum Number of Swaps to Make the Binary String Alternating	Greedy, String
1874	Minimize Product Sum of Two ArraysPremium	Greedy, Array, Sorting
1877	Minimize Maximum Pair Sum in Array	Greedy, Array, Two Pointers +1
1881	Maximum Value after Insertion	Greedy, String
1921	Eliminate Maximum Number of Monsters	Greedy, Array, Sorting
1927	Sum Game	Greedy, Math, String +1
1936	Add Minimum Number of Rungs	Greedy, Array
1946	Largest Number After Mutating Substring	Greedy, Array, String
1953	Maximum Number of Weeks for Which You Can Work	Greedy, Array
1962	Remove Stones to Minimize the Total	Greedy, Array, Heap (Priority Queue)
1963	Minimum Number of Swaps to Make the String Balanced	Stack, Greedy, Two Pointers +1
1968	Array With Elements Not Equal to Average of Neighbors	Greedy, Array, Sorting
1969	Minimum Non-Zero Product of the Array Elements	Greedy, Recursion, Math
1975	Maximum Matrix Sum	Greedy, Array, Matrix
1989	Maximum Number of People That Can Be Caught in TagPremium	Greedy, Array
1996	The Number of Weak Characters in the Game	Stack, Greedy, Array +2
2007	Find Original Array From Doubled Array	Greedy, Array, Hash Table +1
2015	Average Height of Buildings in Each SegmentPremium	Greedy, Array, Sorting +1
2029	Stone Game IX	Greedy, Array, Math +2
2038	Remove Colored Pieces if Both Neighbors are the Same Color	Greedy, Math, String +1
2064	Minimized Maximum of Products Distributed to Any Store	Greedy, Array, Binary Search
2086	Minimum Number of Food Buckets to Feed the Hamsters	Greedy, String, Dynamic Programming
2087	Minimum Cost Homecoming of a Robot in a Grid	Greedy, Array
2091	Removing Minimum and Maximum From Array	Greedy, Array
2098	Subsequence of Size K With the Largest Even SumPremium	Greedy, Array, Sorting
2116	Check if a Parentheses String Can Be Valid	Stack, Greedy, String
2126	Destroying Asteroids	Greedy, Array, Sorting
2131	Longest Palindrome by Concatenating Two Letter Words	Greedy, Array, Hash Table +2
2139	Minimum Moves to Reach Target Score	Greedy, Math
2170	Minimum Operations to Make the Array Alternating	Greedy, Array, Hash Table +1
2171	Removing Minimum Number of Magic Beans	Greedy, Array, Enumeration +2
2178	Maximum Split of Positive Even Integers	Greedy, Math, Backtracking
2182	Construct String With Repeat Limit	Greedy, Hash Table, String +2
2195	Append K Integers With Minimal Sum	Greedy, Array, Math +1
2202	Maximize the Topmost Element After K Moves	Greedy, Array
2207	Maximize Number of Subsequences in a String	Greedy, String, Prefix Sum
2208	Minimum Operations to Halve Array Sum	Greedy, Array, Heap (Priority Queue)
2214	Minimum Health to Beat GamePremium	Greedy, Array
2216	Minimum Deletions to Make Array Beautiful	Stack, Greedy, Array
2233	Maximum Product After K Increments	Greedy, Array, Heap (Priority Queue)
2241	Design an ATM Machine	Greedy, Design, Array
2244	Minimum Rounds to Complete All Tasks	Greedy, Array, Hash Table +1
2268	Minimum Number of KeypressesPremium	Greedy, Hash Table, String +2
2271	Maximum White Tiles Covered by a Carpet	Greedy, Array, Binary Search +3
2279	Maximum Bags With Full Capacity of Rocks	Greedy, Array, Sorting
2285	Maximum Total Importance of Roads	Greedy, Graph, Sorting +1
2294	Partition Array Such That Maximum Difference Is K	Greedy, Array, Sorting
2310	Sum of Numbers With Units Digit K	Greedy, Math, Dynamic Programming +1
2311	Longest Binary Subsequence Less Than or Equal to K	Greedy, Memoization, String +1
2323	Find Minimum Time to Finish All Jobs IIPremium	Greedy, Array, Sorting
2333	Minimum Sum of Squared Difference	Greedy, Array, Binary Search +2
2340	Minimum Adjacent Swaps to Make a Valid ArrayPremium	Greedy, Array
2358	Maximum Number of Groups Entering a Competition	Greedy, Array, Math +1
2375	Construct Smallest Number From DI String	Stack, Greedy, String +1
2384	Largest Palindromic Number	Greedy, Hash Table, String +1
2405	Optimal Partition of String	Greedy, Hash Table, String
2406	Divide Intervals Into Minimum Number of Groups	Greedy, Array, Two Pointers +3
2410	Maximum Matching of Players With Trainers	Greedy, Array, Two Pointers +1
2422	Merge Operations to Turn Array Into a PalindromePremium	Greedy, Array, Two Pointers
2429	Minimize XOR	Greedy, Bit Manipulation
2434	Using a Robot to Print the Lexicographically Smallest String	Stack, Greedy, Hash Table +1
2436	Minimum Split Into Subarrays With GCD Greater Than OnePremium	Greedy, Array, Math +2
2439	Minimize Maximum of Array	Greedy, Array, Binary Search +2
2457	Minimum Addition to Make Integer Beautiful	Greedy, Math
2486	Append Characters to String to Make Subsequence	Greedy, Two Pointers, String
2497	Maximum Star Sum of a Graph	Greedy, Graph, Array +2
2498	Frog Jump II	Greedy, Array, Binary Search
2517	Maximum Tastiness of Candy Basket	Greedy, Array, Binary Search +1
2522	Partition String Into Substrings With Values at Most K	Greedy, String, Dynamic Programming
2530	Maximal Score After Applying K Operations	Greedy, Array, Heap (Priority Queue)
2541	Minimum Operations to Make Array Equal II	Greedy, Array, Math
2548	Maximum Price to Fill a BagPremium	Greedy, Array, Sorting
2554	Maximum Number of Integers to Choose From a Range I	Greedy, Array, Hash Table +2
2557	Maximum Number of Integers to Choose From a Range IIPremium	Greedy, Array, Binary Search +1
2560	House Robber IV	Greedy, Array, Binary Search +1
2567	Minimum Score by Changing Two Elements	Greedy, Array, Sorting
2571	Minimum Operations to Reduce an Integer to 0	Greedy, Bit Manipulation, Dynamic Programming
2576	Find the Maximum Number of Marked Indices	Greedy, Array, Two Pointers +2
2587	Rearrange Array to Maximize Prefix Score	Greedy, Array, Prefix Sum +1
2592	Maximize Greatness of an Array	Greedy, Array, Two Pointers +1
2598	Smallest Missing Non-negative Integer After Operations	Greedy, Array, Hash Table +1
2599	Make the Prefix Sum Non-negativePremium	Greedy, Array, Heap (Priority Queue)
2601	Prime Subtraction Operation	Greedy, Array, Math +2
2607	Make K-Subarray Sums Equal	Greedy, Array, Math +2
2611	Mice and Cheese	Greedy, Array, Sorting +1
2616	Minimize the Maximum Difference of Pairs	Greedy, Array, Binary Search +2
2645	Minimum Additions to Make Valid String	Stack, Greedy, String +1
2673	Make Costs of Paths Equal in a Binary Tree	Greedy, Tree, Array +2
2680	Maximum OR	Greedy, Bit Manipulation, Array +1
2708	Maximum Strength of a Group	Greedy, Bit Manipulation, Array +4
2712	Minimum Cost to Make All Characters Equal	Greedy, String, Dynamic Programming
2734	Lexicographically Smallest String After Substring Operation	Greedy, String
2745	Construct the Longest New String	Greedy, Brainteaser, Math +1
2789	Largest Element in an Array after Merge Operations	Greedy, Array
2800	Shortest String That Contains Three Strings	Greedy, String, Enumeration
2811	Check if it is Possible to Split Array	Greedy, Array, Dynamic Programming
2829	Determine the Minimum Sum of a k-avoiding Array	Greedy, Math
2834	Find the Minimum Possible Sum of a Beautiful Array	Greedy, Math
2844	Minimum Operations to Make a Special Number	Greedy, Math, String +1
2847	Smallest Number With Given Digit ProductPremium	Greedy, Math
2856	Minimum Array Length After Pair Removals	Greedy, Array, Hash Table +3
2870	Minimum Number of Operations to Make Array Empty	Greedy, Array, Hash Table +1
2871	Split Array Into Maximum Number of Subarrays	Greedy, Bit Manipulation, Array
2892	Minimizing Array After Replacing Pairs With Their ProductPremium	Greedy, Array, Dynamic Programming
2895	Minimum Processing Time	Greedy, Array, Sorting
2910	Minimum Number of Groups to Create a Valid Assignment	Greedy, Array, Hash Table
2918	Minimum Equal Sum of Two Arrays After Replacing Zeros	Greedy, Array
2938	Separate Black and White Balls	Greedy, Two Pointers, String
2939	Maximum Xor Product	Greedy, Bit Manipulation, Math
2952	Minimum Number of Coins to be Added	Greedy, Array, Sorting
2957	Remove Adjacent Almost-Equal Characters	Greedy, String, Dynamic Programming
2966	Divide Array Into Arrays With Max Difference	Greedy, Array, Sorting
2967	Minimum Cost to Make Array Equalindromic	Greedy, Array, Math +2
2971	Find Polygon With the Largest Perimeter	Greedy, Array, Prefix Sum +1

Hard (71)

Hard problems
No.	Problem	Topics
0044	Wildcard Matching	Greedy, Recursion, String +1
0135	Candy	Greedy, Array
0321	Create Maximum Number	Stack, Greedy, Array +2
0330	Patching Array	Greedy, Array
0410	Split Array Largest Sum	Greedy, Array, Binary Search +2
0420	Strong Password Checker	Greedy, String, Heap (Priority Queue)
0502	IPO	Greedy, Array, Sorting +1
0517	Super Washing Machines	Greedy, Array
0630	Course Schedule III	Greedy, Array, Sorting +1
0632	Smallest Range Covering Elements from K Lists	Greedy, Array, Hash Table +3
0358	Rearrange String k Distance ApartPremium	Greedy, Hash Table, String +3
0527	Word AbbreviationPremium	Greedy, Trie, Array +2
0757	Set Intersection Size At Least Two	Greedy, Array, Sorting
0765	Couples Holding Hands	Greedy, Depth-First Search, Breadth-First Search +2
0768	Max Chunks To Make Sorted II	Stack, Greedy, Array +2
0857	Minimum Cost to Hire K Workers	Greedy, Array, Sorting +1
0871	Minimum Number of Refueling Stops	Greedy, Array, Dynamic Programming +1
0936	Stamping The Sequence	Stack, Greedy, Queue +1
1147	Longest Chunked Palindrome Decomposition	Greedy, Two Pointers, String +3
1183	Maximum Number of OnesPremium	Greedy, Math, Sorting +1
1199	Minimum Time to Build BlocksPremium	Greedy, Array, Math +1
1326	Minimum Number of Taps to Open to Water a Garden	Greedy, Array, Dynamic Programming
1330	Reverse Subarray To Maximize Array Value	Greedy, Array, Math
1363	Largest Multiple of Three	Greedy, Array, Math +2
1383	Maximum Performance of a Team	Greedy, Array, Sorting +1
1388	Pizza With 3n Slices	Greedy, Array, Dynamic Programming +1
1402	Reducing Dishes	Greedy, Array, Dynamic Programming +1
1505	Minimum Possible Integer After at Most K Adjacent Swaps On Digits	Greedy, Binary Indexed Tree, Segment Tree +1
1520	Maximum Number of Non-Overlapping Substrings	Greedy, String
1526	Minimum Number of Increments on Subarrays to Form a Target Array	Stack, Greedy, Array +2
1537	Get the Maximum Score	Greedy, Array, Two Pointers +1
1585	Check If String Is Transformable With Substring Sort Operations	Greedy, String, Sorting
1665	Minimum Initial Energy to Finish Tasks	Greedy, Array, Sorting
1671	Minimum Number of Removals to Make Mountain Array	Greedy, Array, Binary Search +1
1675	Minimize Deviation in Array	Greedy, Array, Ordered Set +1
1703	Minimum Adjacent Swaps for K Consecutive Ones	Greedy, Array, Prefix Sum +1
1713	Minimum Operations to Make a Subsequence	Greedy, Array, Hash Table +1
1739	Building Boxes	Greedy, Math, Binary Search
1788	Maximize the Beauty of the GardenPremium	Greedy, Array, Hash Table +1
2014	Longest Subsequence Repeated k Times	Greedy, String, Backtracking +2
2030	Smallest K-Length Subsequence With Occurrences of a Letter	Stack, Greedy, String +1
2071	Maximum Number of Tasks You Can Assign	Greedy, Queue, Array +4
2132	Stamping the Grid	Greedy, Array, Matrix +1
2136	Earliest Possible Day of Full Bloom	Greedy, Array, Sorting
2141	Maximum Running Time of N Computers	Greedy, Array, Binary Search +1
2193	Minimum Number of Moves to Make Palindrome	Greedy, Binary Indexed Tree, Two Pointers +1
2234	Maximum Total Beauty of the Gardens	Greedy, Array, Two Pointers +4
2263	Make Array Non-decreasing or Non-increasingPremium	Greedy, Dynamic Programming
2350	Shortest Impossible Sequence of Rolls	Greedy, Array, Hash Table
2366	Minimum Replacements to Sort the Array	Greedy, Array, Math
2412	Minimum Money Required Before Transactions	Greedy, Array, Sorting
2448	Minimum Cost to Make Array Equal	Greedy, Array, Binary Search +2
2449	Minimum Number of Operations to Make Arrays Similar	Greedy, Array, Sorting
2459	Sort Array by Moving Items to Empty SpacePremium	Greedy, Array, Sorting
2472	Maximum Number of Non-overlapping Palindrome Substrings	Greedy, Two Pointers, String +1
2499	Minimum Total Cost to Make Arrays Unequal	Greedy, Array, Hash Table +1
2528	Maximize the Minimum Powered City	Greedy, Queue, Array +3
2551	Put Marbles in Bags	Greedy, Array, Sorting +1
2561	Rearranging Fruits	Greedy, Sort, Array +1
2573	Find the String with LCP	Greedy, Union Find, Array +3
2589	Minimum Time to Complete All Tasks	Stack, Greedy, Array +2
2659	Make Array Empty	Greedy, Binary Indexed Tree, Segment Tree +4
2663	Lexicographically Smallest Beautiful String	Greedy, String
2790	Maximum Number of Groups With Increasing Length	Greedy, Array, Math +2
2813	Maximum Elegance of a K-Length Subsequence	Stack, Greedy, Array +3
2818	Apply Operations to Maximize Score	Stack, Greedy, Array +4
2835	Minimum Operations to Form Subsequence With Target Sum	Greedy, Bit Manipulation, Array
2842	Count K-Subsequences of a String With Maximum Beauty	Greedy, Hash Table, Math +2
2868	The Wording GamePremium	Greedy, Array, Math +3
2897	Apply Operations on Array to Maximize Sum of Squares	Greedy, Bit Manipulation, Array +1
2931	Maximum Spending After Buying Items	Greedy, Array, Matrix +2

Greedy pattern FAQ

What is the greedy pattern?

A greedy algorithm commits to the best-looking option at each step and never reconsiders, which makes it the fastest thing that can possibly work and also the easiest thing to get silently wrong.

How many LeetCode problems use the greedy pattern?

This page lists 346 LeetCode problems that the greedy pattern applies to: 41 Easy, 234 Medium and 71 Hard. 308 of them carry a complete Python solution with complexity analysis.

What is the time complexity of the greedy pattern?

O(n log n), dominated by the sort time and O(1) to O(n) space. The greedy pass itself is a single linear scan; the sort that makes the greedy choice correct is what sets the complexity. When no sort is needed — a running maximum, a reachability check — the whole solution is O(n). The space is the sort's, which in Python means O(n) for Timsort's temporary buffer rather than the O(1) an in-place quicksort would suggest.

When should I use the greedy pattern in an interview?

A local choice can be shown, by an exchange argument, never to rule out an optimal completion. Sorting the input by one well-chosen key makes the right choice obvious at every step.

Which greedy problem should I start with?

LeetCode 409. Longest Palindrome is the lowest-numbered Easy problem on this page, which makes it the usual starting point: the technique is visible without the problem's own complications getting in the way.

What patterns are related to greedy?

Sorting, Dynamic Programming, Heap / Priority Queue, Two Pointers. Problems frequently sit in more than one of these, and the overlap is where the interesting follow-up questions come from.

More ways in: all 22 patterns, the curated study lists, or the full problem list.

What the greedy pattern is

When to use it

The greedy template in Python

Complexity characteristics

Meet the greedy problem you did not practise.

Approach

Approach

Approach

All 346 greedy LeetCode problems

Easy (41)41

Medium (234)234

Hard (71)71

Related patterns

Greedy pattern FAQ

What is the greedy pattern?

How many LeetCode problems use the greedy pattern?

What is the time complexity of the greedy pattern?

When should I use the greedy pattern in an interview?

Which greedy problem should I start with?

What patterns are related to greedy?

Easy (41)

Medium (234)

Hard (71)