📘 Leetcode-for-DSA

A curated collection of LeetCode solutions for mastering Data Structures & Algorithms
Built with ❤️ using LeetHub | Track. Solve. Grow.

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📂 Structure

Each folder is named after the LeetCode problem:

📁 0001-two-sum/
┣ 📄 solution.cpp
┣ 📄 solution.java
┗ 📄 solution.py

Problems are sorted by difficulty and topic (Easy / Medium / Hard).

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🔧 Tech Stack

• 💻 Languages: C++, Java, Python
• 🔁 Sync Tool: LeetHub
• 📚 Platform: LeetCode

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🚀 How to Use

# Step 1: Fork this repo
# Step 2: Clone it locally
git clone https://github.com/Anamicca23/Leetcode-for-DSA.git

# Step 3: Add your own solutions following the naming convention

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ARRAY

Easy Level ❤️

📚 Array - Two Pointer, Hash Table

#	No.	Title	Link	Tags	Level
1	26	Remove Duplicates from Sorted Array		Array, Two Pointers	Easy
2	27	Remove Element		Array, Two Pointers	Easy
3	88	Merge Sorted Array		Array, Two Pointers, Sorting	Easy
4	170	Two Sum III - Data Structure Design		Array, Hash Table, Two Pointers	Easy
5	283	Move Zeroes		Array, Two Pointers	Easy
6	349	Intersection of Two Arrays		Array, Hash Table, Two Pointers	Easy
7	350	Intersection of Two Arrays II		Array, Hash Table, Two Pointers	Easy
8	455	Assign Cookies		Array, Two Pointers, Greedy	Easy
9	821	Shortest Distance to a Character		Array, Two Pointers, String	Easy
10	832	Flipping an Image		Array, Two Pointers, Matrix	Easy
11	905	Sort Array By Parity		Array, Two Pointers, Sorting	Easy
12	922	Sort Array By Parity II		Array, Two Pointers, Sorting	Easy
13	942	DI String Match		Array, Two Pointers, String	Easy
14	977	Squares of a Sorted Array		Array, Two Pointers, Sorting	Easy
15	1089	Duplicate Zeros		Array, Two Pointers	Easy
16	1346	Check If N and Its Double Exist		Array, Hash Table, Two Pointers	Easy
17	1385	Find the Distance Value Between Two Arrays		Array, Two Pointers, Binary Search	Easy
18	1826	Faulty Sensor		Array, Two Pointers	Easy
19	2108	Find First Palindromic String in the Array		Array, Two Pointers, String	Easy
20	2367	Number of Arithmetic Triplets		Array, Hash Table, Two Pointers	Easy
21	2441	Largest Positive Integer That Exists With Its Negative		Array, Hash Table, Two Pointers	Easy
22	2465	Number of Distinct Averages		Array, Hash Table, Two Pointers	Easy
23	2511	Maximum Enemy Forts That Can Be Captured		Array, Two Pointers	Easy
24	2540	Minimum Common Value		Array, Hash Table, Two Pointers	Easy
25	2562	Find the Array Concatenation Value		Array, Two Pointers, Simulation	Easy
26	2570	Merge Two 2D Arrays by Summing Values		Array, Hash Table, Two Pointers	Easy

📚 Array - Sliding Window

#	No.	Title	Link	Tags	Level
1	1456	Maximum Number of Vowels in a Substring of Given Length		String, Sliding Window	Easy
2	1652	Defuse the Bomb		Array, Sliding Window	Easy
3	1984	Minimum Difference Between Highest and Lowest of K Scores		Array, Sliding Window, Sorting	Easy
4	2024	Maximize the Confusion of an Exam		String, Sliding Window, Binary Search	Easy
5	2270	Number of Ways to Split Array		Array, Sliding Window, Prefix Sum	Easy

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Medium Level ❤️❤️❤️

📘 Array - Two Pointer, Sorting, Binary Search, Greedy

#	No.	Title	LC	Tags	Level
1	11	Container With Most Water		Array, Two Pointers, Greedy	Medium
2	15	3Sum		Array, Two Pointers, Sorting	Medium
3	16	3Sum Closest		Array, Two Pointers, Sorting	Medium
4	18	4Sum		Array, Two Pointers, Sorting	Medium
5	31	Next Permutation		Array, Two Pointers	Medium
6	75	Sort Colors		Array, Two Pointers, Sorting	Medium
7	80	Remove Duplicates from Sorted Array II		Array, Two Pointers	Medium
8	167	Two Sum II - Input Array Is Sorted		Array, Two Pointers, Binary Search	Medium
9	189	Rotate Array		Array, Math, Two Pointers	Medium
10	244	Shortest Word Distance II		Array, Hash Table, Two Pointers	Medium
11	251	Flatten 2D Vector		Array, Two Pointers, Design	Medium
12	253	Meeting Rooms II		Array, Two Pointers, Greedy	Medium
13	259	3Sum Smaller		Array, Two Pointers, Binary Search	Medium
14	287	Find the Duplicate Number		Array, Two Pointers, Binary Search	Medium
15	360	Sort Transformed Array		Array, Math, Two Pointers	Medium
16	457	Circular Array Loop		Array, Hash Table, Two Pointers	Medium
17	475	Heaters		Array, Two Pointers, Binary Search	Medium
18	522	Longest Uncommon Subsequence II		Array, Hash Table, Two Pointers	Medium
19	524	Longest Word in Dictionary through Deleting		Array, Two Pointers, String	Medium
20	532	K-diff Pairs in an Array		Array, Hash Table, Two Pointers	Medium
21	581	Shortest Unsorted Continuous Subarray		Array, Two Pointers, Stack	Medium
22	611	Valid Triangle Number		Array, Two Pointers, Binary Search	Medium
23	658	Find K Closest Elements		Array, Two Pointers, Binary Search	Medium
24	723	Candy Crush		Array, Two Pointers, Matrix	Medium
25	795	Number of Subarrays with Bounded Maximum		Array, Two Pointers	Medium
26	809	Expressive Words		Array, Two Pointers, String	Medium
27	825	Friends Of Appropriate Ages		Array, Two Pointers, Binary Search	Medium
28	826	Most Profit Assigning Work		Array, Two Pointers, Binary Search	Medium
29	845	Longest Mountain in Array		Array, Two Pointers	Medium
30	870	Advantage Shuffle		Array, Two Pointers, Greedy	Medium
31	881	Boats to Save People		Array, Two Pointers, Greedy	Medium
32	923	3Sum With Multiplicity		Array, Hash Table, Two Pointers	Medium
33	948	Bag of Tokens		Array, Two Pointers, Greedy	Medium
34	969	Pancake Sorting		Array, Two Pointers, Greedy	Medium
35	986	Interval List Intersections		Array, Two Pointers	Medium
36	1040	Moving Stones Until Consecutive II		Array, Math, Two Pointers	Medium
37	1048	Longest String Chain		Array, Hash Table, Two Pointers	Medium
38	1229	Meeting Scheduler		Array, Two Pointers, Sorting	Medium
39	1471	The k Strongest Values in an Array		Array, Sorting	Medium
40	1498	Subsequences Satisfying the Given Sum Condition		Array, Two Pointers, Binary Search	Medium
41	1508	Range Sum of Sorted Subarray Sums		Array, Two Pointers, Binary Search	Medium
42	1570	Dot Product of Two Sparse Vectors		Array, Hash Table, Two Pointers	Medium
43	1574	Shortest Subarray to be Removed to Make Array Sorted		Array, Two Pointers, Binary Search	Medium
44	1577	Square Equals Product of Two Numbers		Array, Hash Table, Math	Medium
45	1679	Max Number of K-Sum Pairs		Array, Hash Table, Two Pointers	Medium
46	1712	Ways to Split Array Into Three Subarrays		Array, Two Pointers, Binary Search	Medium
47	1813	Sentence Similarity III		Array, Two Pointers, String	Medium
48	1855	Max Distance Between a Pair of Values		Array, Two Pointers, Binary Search	Medium
49	1861	Rotating the Box		Array, Two Pointers, Matrix	Medium
50	1868	Product of Two Run-Length Encoded Arrays		Array, Two Pointers	Medium
51	1877	Minimize Maximum Pair Sum in Array		Array, Two Pointers, Greedy	Medium
52	2105	Watering Plants II		Array, Two Pointers, Simulation	Medium
53	2149	Rearrange Array Elements by Sign		Array, Two Pointers, Simulation	Medium
54	2161	Partition Array According to Given Pivot		Array, Two Pointers, Simulation	Medium
55	2300	Successful Pairs of Spells and Potions		Array, Two Pointers, Binary Search	Medium
56	2332	Latest Time to Catch a Bus		Array, Two Pointers, Binary Search	Medium
57	2406	Divide Intervals Into Min Number of Groups		Array, Two Pointers, Greedy	Medium
58	2410	Max Matching of Players With Trainers		Array, Two Pointers, Greedy	Medium
59	2422	Merge Operations to Turn Array Into Palindrome		Array, Two Pointers, Greedy	Medium
60	2462	Total Cost to Hire K Workers		Array, Two Pointers	Medium
61	2491	Divide Players Into Teams of Equal Skill		Array, Hash Table, Two Pointers	Medium
62	2563	Count the Number of Fair Pairs		Array, Two Pointers, Binary Search	Medium
63	2576	Max Number of Marked Indices		Array, Two Pointers, Binary Search	Medium
64	2592	Maximize Greatness of an Array		Array, Two Pointers, Greedy	Medium

📘 Array - Sliding Window, Binary Search, Hash Table

#	No.	Title	LC Link	Tags	Level
1	209	Minimum Size Subarray Sum		Array, Binary Search, Sliding Window	Medium
2	487	Max Consecutive Ones II		Array, DP, Sliding Window	Medium
3	658	Find K Closest Elements		Array, Two Pointers, Binary Search	Medium
4	713	Subarray Product Less Than K		Array, Sliding Window	Medium
5	718	Maximum Length of Repeated Subarray		Array, Binary Search	Medium
6	904	Fruit Into Baskets		Array, Hash Table, Sliding Window	Medium
7	930	Binary Subarrays With Sum		Array, Hash Table, Sliding Window	Medium
8	978	Longest Turbulent Subarray		Array, DP, Sliding Window	Medium
9	1004	Max Consecutive Ones III		Array, Binary Search, Sliding Window	Medium
10	1031	Max Sum of Two Non-Overlapping Subarrays		Array, DP, Sliding Window	Medium
11	1052	Grumpy Bookstore Owner		Array, Sliding Window	Medium
12	1151	Min Swaps to Group All 1's Together		Array, Sliding Window	Medium
13	1248	Count Number of Nice Subarrays		Array, Hash Table, Math	Medium
14	1343	Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold		Array, Sliding Window	Medium
15	1423	Max Points You Can Obtain from Cards		Array, Sliding Window, Prefix Sum	Medium
16	1438	Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit		Array, Queue, Sliding Window	Medium
17	1477	Two Non-overlapping Subarrays With Target Sum		Array, Hash Table, Binary Search	Medium
18	1493	Longest Subarray of 1's After Deleting One Element		Array, DP, Sliding Window	Medium
19	1658	Min Operations to Reduce X to Zero		Array, Hash Table, Binary Search	Medium
20	1695	Maximum Erasure Value		Array, Hash Table, Sliding Window	Medium
21	1696	Jump Game VI		Array, DP, Queue	Medium
22	1838	Frequency of the Most Frequent Element		Array, Binary Search, Greedy	Medium
23	1852	Distinct Numbers in Each Subarray		Array, Hash Table, Sliding Window	Medium
24	1918	Kth Smallest Subarray Sum		Array, Binary Search, Sliding Window	Medium
25	2090	K Radius Subarray Averages		Array, Sliding Window	Medium
26	2107	Unique Flavors After Sharing K Candies		Array, Hash Table, Sliding Window	Medium
27	2134	Minimum Swaps to Group All 1's Together II		Array, Sliding Window	Medium
28	2260	Minimum Consecutive Cards to Pick Up		Array, Hash Table, Sliding Window	Medium
29	2401	Longest Nice Subarray		Array, Bit Manipulation, Sliding Window	Medium
30	2411	Smallest Subarrays With Max Bitwise OR		Array, Binary Search, Bit Manipulation	Medium
31	2461	Maximum Sum of Distinct Subarrays of Length K		Array, Hash Table, Sliding Window	Medium
32	2537	Count the Number of Good Subarrays		Array, Hash Table, Sliding Window	Medium
33	2555	Maximize Win From Two Segments		Array, Binary Search, Sliding Window	Medium
34	2653	Sliding Subarray Beauty		Array, Hash Table, Sliding Window	Medium

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Hard Level ❤️❤️❤️❤️❤️

📚 Array - Two Pointer, Binary Search

#	No.	Title	Link	Tags	Level
1	42	Trapping Rain Water		Array, Two Pointers, DP, Stack	Hard
2	719	Find K-th Smallest Pair Distance		Array, Two Pointers, Binary Search, Sorting	Hard
3	1537	Get the Maximum Score		Array, Two Pointers, DP, Greedy	Hard
4	1755	Closest Subsequence Sum		Array, Two Pointers, Bit Manipulation	Hard
5	1793	Maximum Score of a Good Subarray		Array, Two Pointers, Binary Search, Stack	Hard
6	2035	Partition Array Into Two Arrays to Minimize Sum Difference		Array, Two Pointers, Binary Search, Bit Manipulation	Hard
7	2234	Maximum Total Beauty of the Gardens		Array, Two Pointers, Binary Search, Greedy	Hard

📚 Array - Sliding Window, Hash Table, Binary Search

#	No.	Title	Link	Tags	Level
1	220	Contains Duplicate III		Array, Sliding Window, Sorting, Ordered Set	Hard
2	239	Sliding Window Maximum		Array, Queue, Sliding Window, Monotonic Queue	Hard
3	480	Sliding Window Median		Array, Hash Table, Sliding Window, Heap	Hard
4	632	Smallest Range Covering Elements from K Lists		Array, Hash Table, Greedy, Sliding Window, Heap	Hard
5	683	K Empty Slots		Array, Sliding Window, Sorting, Ordered Set	Hard
6	862	Shortest Subarray with Sum at Least K		Array, Binary Search, Queue, Sliding Window	Hard
7	992	Subarrays with K Different Integers		Array, Hash Table, Sliding Window	Hard
8	995	Minimum Number of K Consecutive Bit Flips		Array, Bit Manipulation, Queue, Sliding Window	Hard
9	1425	Constrained Subsequence Sum		Array, DP, Queue, Sliding Window	Hard
10	1499	Max Value of Equation		Array, Queue, Sliding Window, Monotonic Queue	Hard
11	1610	Maximum Number of Visible Points		Array, Math, Geometry, Sorting, Sliding Window	Hard
12	1703	Minimum Adjacent Swaps for K Consecutive Ones		Array, Math, Greedy, Sliding Window	Hard
13	2106	Maximum Fruits Harvested After at Most K Steps		Array, Binary Search, Sliding Window, Prefix Sum	Hard
14	2302	Count Subarrays With Score Less Than K		Array, Binary Search, Sliding Window, Prefix Sum	Hard
15	2398	Maximum Number of Robots Within Budget		Array, Binary Search, Queue, Sliding Window	Hard
16	2444	Count Subarrays With Fixed Bounds		Array, Queue, Sliding Window, Monotonic Queue	Hard
17	2524	Maximum Frequency Score of a Subarray		Array, Hash Table, Math, Sliding Window	Hard
18	2528	Maximize the Minimum Powered City		Array, Binary Search, Greedy, Sliding Window	Hard

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TREES AND GRAPHS

📚 Trees and Graphs

#	No.	Title	Link	Tags	Level
1	785	Is Graph Bipartite?		DFS, BFS, Graph, Union Find	Medium
2	823	Binary Trees with Factors		Array, Hash Table, DP	Medium
3	130	Surrounded Regions		Array, DFS, BFS, Matrix, Union Find	Medium
4	752	Open the Lock		Array, Hash Table, String, BFS	Medium
5	802	Find Eventual Safe States		DFS, BFS, Graph, Topological Sort	Medium
6	863	All Nodes Distance K in Binary Tree		Tree, DFS, BFS, Binary Tree	Medium
7	924	Minimize Malware Spread		Array, Hash Table, Graph, Union Find	Hard
8	1306	Jump Game III		Array, DFS, BFS	Medium
9	1489	Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree		Union Find, Graph, MST	Hard
10	1617	Count Subtrees with Max Distance Between Cities		Tree, DFS, Bit Manipulation	Hard
11	1766	Tree of Coprimes		Math, Tree, DFS, Number Theory	Hard
12	1928	Minimum Cost to Reach Destination in Time		Array, DP, Graph	Hard
13	2101	Detonate the Maximum Bombs		Array, Math, DFS, BFS, Graph, Geometry	Medium
14	2322	Minimum Score After Removals on a Tree		Tree, DFS, Bit Manipulation	Hard
15	2440	Create Components with Same Value		Array, Math, Tree, DFS, Graph	Hard
16	2493	Divide Nodes Into the Maximum Number of Groups		BFS, Union Find, Graph	Hard
17	2509	Cycle Length Queries in a Tree		Tree, DFS, Binary Lifting	Hard
18	2646	Minimize the Total Price of the Trips		Array, DFS, Tree, DP, Binary Tree	Hard
19	685	Redundant Connection II		DFS, Graph, Union Find, Tree	Hard

📚 BFS / DFS (Shortest Paths)

#	No.	Title	Link	Tags	Level
1	433	Minimum Genetic Mutation		Hash Table, String, BFS	Medium
2	815	Bus Routes		Array, Hash Table, BFS	Hard
3	1091	Shortest Path in Binary Matrix		Array, BFS, Matrix	Medium
4	1786	Number of Restricted Paths from First to Last Node		Graph, DFS, BFS, Heap, DP	Medium
5	1926	Nearest Exit from Entrance in Maze		Array, BFS, Matrix	Medium
6	2503	Maximum Number of Points from Grid Queries		Array, BFS, Graph, Sorting, Heap	Hard
7	2577	Minimum Time to Visit a Cell in a Grid		Array, BFS, Matrix, Heap	Hard

📚 Hashmaps

#	No.	Title	Link	Tags	Level
1	1657	Determine if Two Strings Are Close		Hash Table, String, Sorting	Medium
2	1912	Design Movie Rental System		Array, Hash Table, Design, Heap, Ordered Set	Hard
3	2718	Sum of Matrix After Queries		Array, Hash Table, Matrix	Medium

📚 Binary Trees

#	No.	Title	Link	Tags	Level
1	513	Find Bottom Left Tree Value		Tree, DFS, BFS, Binary Tree	Medium
2	623	Add One Row to Tree		Tree, DFS, BFS, Binary Tree	Medium
3	1080	Insufficient Nodes in Root to Leaf Paths		Tree, DFS, Binary Tree	Medium
4	1104	Path in Zigzag Labelled Binary Tree		Math, Tree, Binary Tree	Medium
5	1145	Binary Tree Coloring Game		Tree, DFS, Binary Tree	Medium
6	1367	Linked List in Binary Tree		Linked List, Tree, DFS, Binary Tree	Medium
7	1530	Number of Good Leaf Nodes Pairs		Tree, DFS, Binary Tree	Medium
8	2096	Step-by-Step Directions from a Binary Tree Node to Another		String, Tree, DFS, Binary Tree	Medium

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BITWISE OPERATIONS

📚 Bitwise Operations

#	No.	Title	Link	Tags	Level
1	1404	Number of Steps to Reduce a Number in Binary Representation to One		String, Bit Manipulation	Medium
2	1738	Find Kth Largest XOR Coordinate Value		Array, Bit Manipulation, Prefix Sum, Heap	Medium
3	2683	Neighboring Bitwise XOR		Array, Bit Manipulation	Medium
4	2835	Minimum Operations to Form Subsequence with Target Sum		Array, Bit Manipulation, Greedy	Hard

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RECURSION

📚 Recursion

#	No.	Title	Link	Tags	Level
1	842	Split Array into Fibonacci Sequence		String, Backtracking, Greedy	Medium
2	967	Numbers with Same Consecutive Differences		DFS, BFS, Backtracking	Medium
3	1601	Maximum Number of Achievable Transfer Requests		Array, Backtracking, Bit Manipulation, Enumeration	Hard
4	2698	Find the Punishment Number of an Integer		Math, Backtracking	Medium

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SLIDING WINDOW

📚 Sliding Window (Additional)

#	No.	Title	Link	Tags	Level
1	2747	Count Zero Request Servers		Array, Hash Table, Binary Search, Sliding Window	Medium
2	2762	Continuous Subarrays		Array, Sliding Window, Queue, Ordered Set, Heap	Medium
3	2781	Length of the Longest Valid Substring		Array, Hash Table, String, Sliding Window	Hard

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STACK

📚 Stack

#	No.	Title	Link	Tags	Level
1	84	Largest Rectangle in Histogram		Array, Stack, Monotonic Stack	Hard
2	735	Asteroid Collision		Array, Stack, Simulation	Medium
3	907	Sum of Subarray Minimums		Array, Stack, DP, Monotonic Stack	Medium
4	1209	Remove All Adjacent Duplicates in String II		String, Stack	Medium
5	1944	Number of Visible People in a Queue		Array, Stack, Monotonic Stack	Hard
6	2334	Subarray with Elements Greater Than Varying Threshold		Array, Stack, Union Find, Monotonic Stack	Hard
7	2751	Robot Collisions		Array, Stack, Sorting, Simulation	Hard
8	2818	Apply Operations to Maximize Score		Array, Math, Stack, Greedy, Monotonic Stack	Hard
9	2866	Beautiful Towers II		Array, Stack, Monotonic Stack	Medium

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DYNAMIC PROGRAMMING

📚 Dynamic Programming

#	No.	Title	Link	Tags	Level
1	354	Russian Doll Envelopes		Array, Binary Search, DP, Sorting	Hard
2	552	Student Attendance Record II		DP	Hard
3	673	Number of Longest Increasing Subsequence		Array, Binary Search, DP, Segment Tree	Medium
4	712	Minimum ASCII Delete Sum for Two Strings		String, DP	Medium
5	935	Knight Dialer		DP	Medium
6	956	Tallest Billboard		Array, DP	Hard
7	1027	Longest Arithmetic Subsequence		Array, Hash Table, Binary Search, DP	Medium
8	1218	Longest Arithmetic Subsequence of Given Difference		Array, Hash Table, DP	Medium
9	1220	Count Vowels Permutation		DP, Math	Hard
10	1335	Minimum Difficulty of a Job Schedule		Array, DP	Hard
11	1575	Count All Possible Routes		Array, DP, Memoization	Hard
12	1749	Maximum Absolute Sum of Any Subarray		Array, DP	Medium
13	1751	Maximum Number of Events That Can Be Attended II		Array, Binary Search, DP, Sorting	Hard
14	1824	Minimum Sideway Jumps		Array, DP, Greedy	Medium
15	1911	Maximum Alternating Subsequence Sum		Array, DP, Greedy	Medium
16	2746	Decremental String Concatenation		String, DP	Medium
17	2763	Sum of Imbalance Numbers of All Subarrays		Array, Hash Table, Counting	Hard

📚 Bitmasking DP

#	No.	Title	Link	Tags	Level
1	1178	Number of Valid Words for Each Puzzle		Array, Hash Table, String, Bit Manipulation, Trie	Hard
2	1269	Number of Ways to Stay in the Same Place After Some Steps		DP	Hard
3	1434	Number of Ways to Wear Different Hats to Each Other		Array, DP, Bit Manipulation	Hard
4	1542	Find Longest Awesome Substring		Hash Table, String, Bit Manipulation	Hard
5	1799	Maximize Score After N Operations		Array, Math, DP, Backtracking, Bit Manipulation	Hard
6	1986	Minimum Number of Work Sessions to Finish the Tasks		Array, DP, Backtracking, Bit Manipulation	Medium
7	2002	Maximum Product of the Length of Two Palindromic Subsets		Array, String, DP, Bit Manipulation	Hard
8	2741	Special Permutations		Array, DP, Bit Manipulation	Medium

📚 Digit DP

#	No.	Title	Link	Tags	Level
1	600	Non-negative Integers Without Consecutive Ones		DP, Bit Manipulation	Hard
2	2376	Count Special Integers		Math, DP	Hard
3	2719	Count of Integers		Math, String, DP	Hard
4	2801	Count Stepping Numbers in Range		Math, String, DP	Hard

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LINKED LISTS

📚 Linked Lists

#	No.	Title	Link	Tags	Level
1	92	Reverse Linked List II		Linked List	Medium
2	725	Split Linked List in Parts		Linked List	Medium
3	1669	Merge In Between Linked Lists		Linked List	Medium
4	2095	Delete the Middle Node of a Linked List		Linked List, Two Pointers	Medium
5	2487	Remove Nodes from Linked List		Linked List, Stack, Recursion	Medium

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SUFFIX AND PREFIX ARRAY

📚 Suffix and Prefix Array

#	No.	Title	Link	Tags	Level
1	456	132 Pattern		Array, Binary Search, Stack, Monotonic Stack	Medium
2	768	Max Chunks To Make Sorted II		Array, Stack, Greedy, Sorting, Monotonic Stack	Hard
3	1653	Minimum Deletions to Make String Balanced		String, Stack, DP	Medium
4	2017	Grid Game		Array, Matrix, Prefix Sum	Medium
5	2448	Minimum Cost to Make Array Equal		Array, Binary Search, Prefix Sum	Medium
6	2483	Minimum Penalty for a Shop		String, Prefix Sum	Medium
7	2780	Minimum Index of a Valid Split		Array, Hash Table, Sorting	Medium

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DSU (DISJOINT SET UNION)

📚 DSU (Union-Find)

#	No.	Title	Link	Tags	Level
1	721	Accounts Merge		Array, Hash Table, String, DFS, BFS, DSU	Medium
2	827	Making a Large Island		Array, DFS, BFS, Union Find, Matrix	Hard
3	990	Satisfiability of Equality Equations		Array, String, Graph, Union Find	Medium
4	1627	Graph Connectivity with Threshold		Array, Math, Union Find	Hard
5	2076	Process Restricted Friend Requests		Array, Union Find	Hard

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BINARY SEARCH

📚 Binary Search (Additional)

#	No.	Title	Link	Tags	Level
1	410	Split Array Largest Sum		Array, Binary Search, DP, Greedy	Hard
2	668	Kth Smallest Number in Multiplication Table		Math, Binary Search	Hard
3	1146	Snapshot Array		Array, Hash Table, Binary Search, Design	Medium
4	1760	Minimum Limit of Balls in a Bag		Array, Binary Search	Medium
5	1898	Maximum Number of Removable Characters		Array, String, Binary Search	Medium
6	2080	Range Frequency Queries		Array, Hash Table, Binary Search, Design	Medium

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SORTING

📚 Sorting

#	No.	Title	Link	Tags	Level
1	435	Non-overlapping Intervals		Array, Greedy, Sorting	Medium
2	452	Minimum Number of Arrows to Burst Balloons		Array, Greedy, Sorting	Medium
3	786	K-th Smallest Prime Fraction		Array, Binary Search, Sorting, Heap	Medium
4	1847	Closest Room		Array, Binary Search, Sorting	Hard
5	1851	Minimum Interval to Include Each Query		Array, Binary Search, Greedy, Sorting, Heap	Hard
6	2551	Put Marbles in Bags		Array, Greedy, Sorting, Heap	Hard
7	2731	Movement of Robots		Array, Math, Prefix Sum, Sorting	Medium

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STRING

📚 String

#	No.	Title	Link	Tags	Level
1	214	Shortest Palindrome		String, Rolling Hash, String Matching	Hard
2	1044	Longest Duplicate Substring		String, Binary Search, Rolling Hash, Suffix Array	Hard
3	1147	Longest Chunked Palindrome Decomposition		String, Two Pointers, Greedy, Hashing	Hard
4	1668	Maximum Repeating Substring		String, DP, String Matching	Easy
5	2223	Sum of Scores of Built Strings		String, Binary Search, Rolling Hash, Z-Algorithm	Hard
6	2430	Maximum Deletions on a String		String, DP, Rolling Hash	Hard
7	2734	Lexicographically Smallest String After Substring Operation		String, Greedy	Medium

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COUNTING

📚 Counting

#	No.	Title	Link	Tags	Level
1	828	Count Unique Characters of All Substrings of a Given String		Hash Table, String, DP	Hard
2	1588	Sum of All Odd Length Subarrays		Array, Math, Prefix Sum	Easy
3	2514	Count Anagrams		Hash Table, Math, String, Combinatorics	Hard

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LINE SWEEP

📚 Line Sweep

#	No.	Title	Link	Tags	Level
1	732	My Calendar III		Binary Search, Design, Segment Tree, Ordered Set	Hard
2	1943	Describe the Painting		Array, Hash Table, Sorting, Prefix Sum	Medium
3	2251	Number of Flowers in Full Bloom		Array, Hash Table, Binary Search, Sorting, Prefix Sum	Hard
4	2779	Maximum Beauty of an Array After Applying Operation		Array, Binary Search, Sliding Window, Sorting	Medium

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RE-ROOTING

📚 Re-rooting

#	No.	Title	Link	Tags	Level
1	310	Minimum Height Trees		DFS, BFS, Graph, Topological Sort	Medium
2	2538	Difference Between Maximum and Minimum Price Sum		Array, Tree, DFS	Hard
3	2581	Count Number of Possible Root Nodes		Tree, DFS, Hashing	Hard

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TRIE

📚 Trie

#	No.	Title	Link	Tags	Level
1	745	Prefix and Suffix Search		Design, Trie, Hash Table, String	Hard
2	1938	Maximum Genetic Difference Query		Array, String, Bit Manipulation, Trie	Hard
3	2416	Sum of Prefix Scores of Strings		Array, String, Trie, Counting	Hard

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✅ Best Practices

• Keep filenames clean (solution.cpp, solution.py)
• Add comments where necessary
• Group problems by topics (optional but encouraged)

---

🤝 Contributing

Want to help expand this repository?

1. Fork it 🍴
2. Create your feature branch (git checkout -b new-solution)
3. Commit your changes (git commit -m 'Added XYZ problem')
4. Push to the branch (git push origin new-solution)
5. Open a PR 🚀

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🌟 Support & Recognition

If this project helps you:

• ⭐ Star the repo
• 🔁 Share it with peers preparing for coding interviews
• 🧠 Keep coding and contribute back!

---

📄 License

This project is licensed under the MIT License. See the LICENSE file for details.

---

👤 About

Made with ☕ and code by Anamicca23

Let's crack those coding interviews one problem at a time!

LeetCode Topics

Array

Problem Name	Difficulty
0048-rotate-image	Medium
0396-rotate-function	Medium
0874-walking-robot-simulation	Medium
1536-minimum-swaps-to-arrange-a-binary-grid	Medium
1559-detect-cycles-in-2d-grid	Medium
1582-special-positions-in-a-binary-matrix	Easy
1594-maximum-non-negative-product-in-a-matrix	Medium
1722-minimize-hamming-distance-after-swap-operations	Medium
1727-largest-submatrix-with-rearrangements	Medium
1848-minimum-distance-to-the-target-element	Easy
1855-maximum-distance-between-a-pair-of-values	Medium
1861-rotating-the-box	Medium
1878-get-biggest-three-rhombus-sums-in-a-grid	Medium
1886-determine-whether-matrix-can-be-obtained-by-rotation	Easy
1914-cyclically-rotating-a-grid	Medium
1980-find-unique-binary-string	Medium
2078-two-furthest-houses-with-different-colors	Easy
2452-words-within-two-edits-of-dictionary	Medium
2463-minimum-total-distance-traveled	Hard
2515-shortest-distance-to-target-string-in-a-circular-array	Easy
2573-find-the-string-with-lcp	Hard
2615-sum-of-distances	Medium
2751-robot-collisions	Hard
2906-construct-product-matrix	Medium
2946-matrix-similarity-after-cyclic-shifts	Easy
3070-count-submatrices-with-top-left-element-and-sum-less-than-k	Medium
3212-count-submatrices-with-equal-frequency-of-x-and-y	Medium
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3418-maximum-amount-of-money-robot-can-earn	Medium
3464-maximize-the-distance-between-points-on-a-square	Hard
3488-closest-equal-element-queries	Medium
3546-equal-sum-grid-partition-i	Medium
3548-equal-sum-grid-partition-ii	Hard
3567-minimum-absolute-difference-in-sliding-submatrix	Medium
3629-minimum-jumps-to-reach-end-via-prime-teleportation	Medium
3643-flip-square-submatrix-vertically	Easy
3653-xor-after-range-multiplication-queries-i	Medium
3655-xor-after-range-multiplication-queries-ii	Hard
3660-jump-game-ix	Medium
3661-maximum-walls-destroyed-by-robots	Hard
3740-minimum-distance-between-three-equal-elements-i	Easy
3741-minimum-distance-between-three-equal-elements-ii	Medium
3742-maximum-path-score-in-a-grid	Medium
3761-minimum-absolute-distance-between-mirror-pairs	Medium

Greedy

Problem Name	Difficulty
1536-minimum-swaps-to-arrange-a-binary-grid	Medium
1727-largest-submatrix-with-rearrangements	Medium
2078-two-furthest-houses-with-different-colors	Easy
2573-find-the-string-with-lcp	Hard
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3474-lexicographically-smallest-generated-string	Hard
3600-maximize-spanning-tree-stability-with-upgrades	Hard

Matrix

Problem Name	Difficulty
0048-rotate-image	Medium
1536-minimum-swaps-to-arrange-a-binary-grid	Medium
1559-detect-cycles-in-2d-grid	Medium
1582-special-positions-in-a-binary-matrix	Easy
1594-maximum-non-negative-product-in-a-matrix	Medium
1727-largest-submatrix-with-rearrangements	Medium
1861-rotating-the-box	Medium
1878-get-biggest-three-rhombus-sums-in-a-grid	Medium
1886-determine-whether-matrix-can-be-obtained-by-rotation	Easy
1914-cyclically-rotating-a-grid	Medium
2573-find-the-string-with-lcp	Hard
2906-construct-product-matrix	Medium
2946-matrix-similarity-after-cyclic-shifts	Easy
3070-count-submatrices-with-top-left-element-and-sum-less-than-k	Medium
3212-count-submatrices-with-equal-frequency-of-x-and-y	Medium
3418-maximum-amount-of-money-robot-can-earn	Medium
3546-equal-sum-grid-partition-i	Medium
3548-equal-sum-grid-partition-ii	Hard
3567-minimum-absolute-difference-in-sliding-submatrix	Medium
3643-flip-square-submatrix-vertically	Easy
3742-maximum-path-score-in-a-grid	Medium

String

Problem Name	Difficulty
0657-robot-return-to-origin	Easy
0796-rotate-string	Easy
1320-minimum-distance-to-type-a-word-using-two-fingers	Hard
1415-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n	Medium
1545-find-kth-bit-in-nth-binary-string	Medium
1758-minimum-changes-to-make-alternating-binary-string	Easy
1784-check-if-binary-string-has-at-most-one-segment-of-ones	Easy
1888-minimum-number-of-flips-to-make-the-binary-string-alternating	Medium
1980-find-unique-binary-string	Medium
2075-decode-the-slanted-ciphertext	Medium
2452-words-within-two-edits-of-dictionary	Medium
2515-shortest-distance-to-target-string-in-a-circular-array	Easy
2573-find-the-string-with-lcp	Hard
2833-furthest-point-from-origin	Easy
2839-check-if-strings-can-be-made-equal-with-operations-i	Easy
2840-check-if-strings-can-be-made-equal-with-operations-ii	Medium
3474-lexicographically-smallest-generated-string	Hard

Recursion

Problem Name	Difficulty
1545-find-kth-bit-in-nth-binary-string	Medium

Simulation

Problem Name	Difficulty
0657-robot-return-to-origin	Easy
0874-walking-robot-simulation	Medium
1545-find-kth-bit-in-nth-binary-string	Medium
1914-cyclically-rotating-a-grid	Medium
2069-walking-robot-simulation-ii	Medium
2075-decode-the-slanted-ciphertext	Medium
2751-robot-collisions	Hard
2946-matrix-similarity-after-cyclic-shifts	Easy
3653-xor-after-range-multiplication-queries-i	Medium

Dynamic Programming

Problem Name	Difficulty
0396-rotate-function	Medium
0788-rotated-digits	Medium
1320-minimum-distance-to-type-a-word-using-two-fingers	Hard
1594-maximum-non-negative-product-in-a-matrix	Medium
1888-minimum-number-of-flips-to-make-the-binary-string-alternating	Medium
2463-minimum-total-distance-traveled	Hard
2573-find-the-string-with-lcp	Hard
3129-find-all-possible-stable-binary-arrays-i	Medium
3130-find-all-possible-stable-binary-arrays-ii	Hard
3418-maximum-amount-of-money-robot-can-earn	Medium
3660-jump-game-ix	Medium
3661-maximum-walls-destroyed-by-robots	Hard
3742-maximum-path-score-in-a-grid	Medium

Sliding Window

Problem Name	Difficulty
1888-minimum-number-of-flips-to-make-the-binary-string-alternating	Medium

Hash Table

Problem Name	Difficulty
0874-walking-robot-simulation	Medium
1980-find-unique-binary-string	Medium
2615-sum-of-distances	Medium
2840-check-if-strings-can-be-made-equal-with-operations-ii	Medium
3488-closest-equal-element-queries	Medium
3548-equal-sum-grid-partition-ii	Hard
3629-minimum-jumps-to-reach-end-via-prime-teleportation	Medium
3740-minimum-distance-between-three-equal-elements-i	Easy
3741-minimum-distance-between-three-equal-elements-ii	Medium
3761-minimum-absolute-distance-between-mirror-pairs	Medium

Backtracking

Problem Name	Difficulty
1415-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n	Medium
1980-find-unique-binary-string	Medium

Prefix Sum

Problem Name	Difficulty
1878-get-biggest-three-rhombus-sums-in-a-grid	Medium
2615-sum-of-distances	Medium
2906-construct-product-matrix	Medium
3070-count-submatrices-with-top-left-element-and-sum-less-than-k	Medium
3129-find-all-possible-stable-binary-arrays-i	Medium
3130-find-all-possible-stable-binary-arrays-ii	Hard
3212-count-submatrices-with-equal-frequency-of-x-and-y	Medium
3546-equal-sum-grid-partition-i	Medium
3548-equal-sum-grid-partition-ii	Hard

Bit Manipulation

Problem Name	Difficulty
1009-complement-of-base-10-integer	Easy

Binary Search

Problem Name	Difficulty
1855-maximum-distance-between-a-pair-of-values	Medium
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3464-maximize-the-distance-between-points-on-a-square	Hard
3488-closest-equal-element-queries	Medium
3600-maximize-spanning-tree-stability-with-upgrades	Hard
3661-maximum-walls-destroyed-by-robots	Hard

Union-Find

Problem Name	Difficulty
1559-detect-cycles-in-2d-grid	Medium
1722-minimize-hamming-distance-after-swap-operations	Medium
2573-find-the-string-with-lcp	Hard
3600-maximize-spanning-tree-stability-with-upgrades	Hard

Graph Theory

Problem Name	Difficulty
3600-maximize-spanning-tree-stability-with-upgrades	Hard

Minimum Spanning Tree

Problem Name	Difficulty
3600-maximize-spanning-tree-stability-with-upgrades	Hard

Math

Problem Name	Difficulty
0048-rotate-image	Medium
0396-rotate-function	Medium
0788-rotated-digits	Medium
1622-fancy-sequence	Hard
1878-get-biggest-three-rhombus-sums-in-a-grid	Medium
2946-matrix-similarity-after-cyclic-shifts	Easy
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium
3464-maximize-the-distance-between-points-on-a-square	Hard
3629-minimum-jumps-to-reach-end-via-prime-teleportation	Medium
3761-minimum-absolute-distance-between-mirror-pairs	Medium
3783-mirror-distance-of-an-integer	Easy

Heap (Priority Queue)

Problem Name	Difficulty
1878-get-biggest-three-rhombus-sums-in-a-grid	Medium
3296-minimum-number-of-seconds-to-make-mountain-height-zero	Medium

Design

Problem Name	Difficulty
1622-fancy-sequence	Hard
2069-walking-robot-simulation-ii	Medium

Segment Tree

Problem Name	Difficulty
1622-fancy-sequence	Hard

Sorting

Problem Name	Difficulty
1727-largest-submatrix-with-rearrangements	Medium
1878-get-biggest-three-rhombus-sums-in-a-grid	Medium
2463-minimum-total-distance-traveled	Hard
2751-robot-collisions	Hard
2840-check-if-strings-can-be-made-equal-with-operations-ii	Medium
3464-maximize-the-distance-between-points-on-a-square	Hard
3567-minimum-absolute-difference-in-sliding-submatrix	Medium
3661-maximum-walls-destroyed-by-robots	Hard

Two Pointers

Problem Name	Difficulty
0061-rotate-list	Medium
1855-maximum-distance-between-a-pair-of-values	Medium
1861-rotating-the-box	Medium
3643-flip-square-submatrix-vertically	Easy

Enumeration

Problem Name	Difficulty
3546-equal-sum-grid-partition-i	Medium
3548-equal-sum-grid-partition-ii	Hard

String Matching

Problem Name	Difficulty
0796-rotate-string	Easy
3474-lexicographically-smallest-generated-string	Hard

Stack

Problem Name	Difficulty
2751-robot-collisions	Hard

Divide and Conquer

Problem Name	Difficulty
3653-xor-after-range-multiplication-queries-i	Medium
3655-xor-after-range-multiplication-queries-ii	Hard

Depth-First Search

Problem Name	Difficulty
1559-detect-cycles-in-2d-grid	Medium
1722-minimize-hamming-distance-after-swap-operations	Medium

Trie

Problem Name	Difficulty
2452-words-within-two-edits-of-dictionary	Medium

Counting

Problem Name	Difficulty
2833-furthest-point-from-origin	Easy

Geometry

Problem Name	Difficulty
3464-maximize-the-distance-between-points-on-a-square	Hard

Breadth-First Search

Problem Name	Difficulty
1559-detect-cycles-in-2d-grid	Medium
3629-minimum-jumps-to-reach-end-via-prime-teleportation	Medium

Linked List

Problem Name	Difficulty
0061-rotate-list	Medium

Number Theory

Problem Name	Difficulty
3629-minimum-jumps-to-reach-end-via-prime-teleportation	Medium