DSA Sheet | DSA Doctor

PHASE 1 : FUNDAMENTALS & LINEAR DATA STRUCTURES64 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
1	Arrays	Array Basics	Find Element at a Given Index	GeeksForGeeks	★★★★★
2			Min and Max in Array	GeeksForGeeks	★☆☆☆☆
3			Sum of Array	GeeksForGeeks	★☆☆☆☆
4			Sum of Digits	GeeksForGeeks	★☆☆☆☆
5			Check If Array is Sorted	GeeksForGeeks	★☆☆☆☆
6			Alternates In Array	GeeksForGeeks	★☆☆☆☆
7		Core Manipulations	Remove Duplicates from Array	LeetCode	★★☆☆☆
8			Second Largest in Array	GeeksForGeeks	★★☆☆☆
9			Reverse an Array	GeeksForGeeks	★★☆☆☆
10			Missing Number	LeetCode	★★☆☆☆
11			Segregate 0s and 1s	GeeksForGeeks	★★★★★
12			Maximum Consecutive Ones	LeetCode	★★☆☆☆
13			Palindromic Array	GeeksForGeeks	★★☆☆☆
14			Move Zeroes to End	LeetCode	★★☆☆☆
15			Sort array with 0's 1's and 2's (Dutch Flag)	LeetCode	★★☆☆☆
16		Intermediate Problems	Equilibrium Point	GeeksForGeeks	★★★☆☆
17			Reverse Integer	LeetCode	★★★☆☆
18			Leaders in Array	GeeksForGeeks	★★★☆☆
19			Increasing Array	Practice	★★★☆☆
20			Rearrange Array Elements by Sign	LeetCode	★★★☆☆
21			Rotate Array by One	GeeksForGeeks	★★★☆☆
22			Majority Element I (Boyer - Moore)	LeetCode	★★★☆☆
23		Advanced Problems	Rotate Array by K steps	LeetCode	★★★★☆
24			Wiggle Sort II	LeetCode	★★★★☆
25			Majority Element II	LeetCode	★★★★☆
26			Best Time to Buy and Sell Stock	LeetCode	★★★★☆
27			Next Permutation	LeetCode	★★★★☆
28			Maximum Value Of Expression	GeeksForGeeks	★★★★☆
29			First Missing Positive	LeetCode	★★★★★
✓ Arrays completed — 29 questions
30	2D Arrays	Matrix Basics	Sum of elements in a matrix	GeeksForGeeks	★★☆☆☆
31			Count Number Of Zeroes	GeeksForGeeks	★★☆☆☆
32			Count Negative Numbers in a matrix	LeetCode	★★☆☆☆
33			Matrix Diagonal Sum	LeetCode	★★☆☆☆
34		Matrix Operations	Addition of Two Square Matrix	GeeksForGeeks	★★★☆☆
35			Multiply Matrices	GeeksForGeeks	★★★☆☆
36			Transpose Matrix	LeetCode	★★★☆☆
37		Advanced Matrix	Spiral Matrix	LeetCode	★★★★☆
38			ZigZag Matrix	GeeksForGeeks	★★★★☆
39			Rotate Matrix (90°)	LeetCode	★★★★☆
40			Determine Whether matrix can be obtained by rotation	LeetCode	★★★★☆
41			Set Matrix Zeroes	LeetCode	★★★★★
✓ 2D Arrays completed — 12 questions
42	Basic Maths	Number Theory Basics	Check if a number is Armstrong	GeeksForGeeks	★☆☆☆☆
43			Print all Divisors of a Number	GeeksForGeeks	★☆☆☆☆
44			Check if a number is Prime	GeeksForGeeks	★☆☆☆☆
45			GCD / HCF of 2 numbers	GeeksForGeeks	★☆☆☆☆
46			Prime Factorisation of a Number	GeeksForGeeks	★★☆☆☆
47			Count Primes in range L to R	GeeksForGeeks	★★★☆☆
✓ Basic Maths completed — 6 questions
48	Strings	String Fundamentals	Maximum Occuring Character	GeeksForGeeks	★☆☆☆☆
49			Remove Spaces	GeeksForGeeks	★☆☆☆☆
50			Print first letter of every word in the string	GeeksForGeeks	★★☆☆☆
51			Remove Consecutive Characters	GeeksForGeeks	★★☆☆☆
52			Valid Palindrome	LeetCode	★★☆☆☆
53			Valid Anagram	LeetCode	★★☆☆☆
54			Isomorphic Strings	LeetCode	★★☆☆☆
55		String Manipulation	Delete Characters To Make Fancy String	LeetCode	★★★☆☆
56			Reverse Words in a String	LeetCode	★★★☆☆
57			String to integer (atoi)	LeetCode	★★★☆☆
58			Roman to integer	LeetCode	★★★☆☆
59			Rotate String	LeetCode	★★★☆☆
60			Longest common prefix	LeetCode	★★★☆☆
61		Advanced Problems	Longest palindromic substring	LeetCode	★★★★☆
62			Multiply Two Strings	GeeksForGeeks	★★★★☆
63			Maximum Nesting Depth of the Parentheses	LeetCode	★★★★☆
64			Beauty Of All substrings	LeetCode	★★★★☆
✓ Strings completed — 17 questions

PHASE 2 : SEARCHING ALGORITHM37 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
65	Binary Search	BS on 1D Array Basics	Search X in sorted array	LeetCode	★★☆☆☆
66			Lower Bound	GeeksForGeeks	★★☆☆☆
67			Upper Bound	GeeksForGeeks	★★☆☆☆
68			Search insert position	LeetCode	★★☆☆☆
69			Floor In Sorted Array	GeeksForGeeks	★★☆☆☆
70			Ceil In Sorted Array	GeeksForGeeks	★★☆☆☆
71			Guess Number Higher or Lower API	LeetCode	★★☆☆☆
72			First 1 in a Sorted Binary Array	GeeksForGeeks	★★☆☆☆
73			Kth Missing Positive Number	LeetCode	★★☆☆☆
74			Find minimum in Rotated Sorted Array	LeetCode	★★☆☆☆
75		BS on 1D Array Intermediate	First and last occurrence	LeetCode	★★★☆☆
76			Search in rotated sorted array-I	LeetCode	★★★☆☆
77			Search in rotated sorted array-II	LeetCode	★★★☆☆
78			Single element in a Sorted Array	LeetCode	★★★☆☆
79			Find kth Rotation	GeeksForGeeks	★★★☆☆
80			Find Peak Element	LeetCode	★★★☆☆
81		BS on 2D Arrays	Count Negative Numbers in a Sorted Matrix	LeetCode	★★☆☆☆
82			Find row with maximum 1's	LeetCode	★★☆☆☆
83			Search a 2D Matrix I	LeetCode	★★☆☆☆
84			Search a 2D Matrix II	LeetCode	★★★☆☆
85			Find Peak Element - II	LeetCode	★★★★☆
86			Median in a row-wise sorted Matrix	GeeksForGeeks	★★★★☆
87		BS on Answer	Sqrt (x)	LeetCode	★★☆☆☆
88			Valid Perfect Square	LeetCode	★★☆☆☆
89			Find Nth root of a number	GeeksForGeeks	★★★☆☆
90			Koko eating bananas	LeetCode	★★★☆☆
91			Find the Smallest Divisor Given a Threshold	LeetCode	★★★☆☆
92			Minimum Speed to Arrive on Time	LeetCode	★★★☆☆
93			Minimum days to make M bouquets	LeetCode	★★★☆☆
94			Capacity to Ship Packages Within D Days	LeetCode	★★★☆☆
95			Book Allocation Problem	GeeksForGeeks	★★★☆☆
96			Split Array Largest Sum	LeetCode	★★★★☆
97			Painter's Partition Problem	GeeksForGeeks	★★★★☆
98			K-th element of two sorted Arrays	GeeksForGeeks	★★★★☆
99			Aggressive Cows	GeeksForGeeks	★★★★★
100			Minimize Max Distance to Gas Station	GeeksForGeeks	★★★★★
101			Median of Two Sorted Arrays	LeetCode	★★★★★
✓ Binary Search completed — 37 questions

PHASE 3 : ALGORITHMIC THINKING19 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
102	Recursion	Introduction to Recursion	Print 1 to N without using loops	GeeksForGeeks	★☆☆☆☆
103			Print N to 1 without loop	Practice	★☆☆☆☆
104			Sum of first N numbers	GeeksForGeeks	★☆☆☆☆
105			Factorial of a given number	GeeksForGeeks	★☆☆☆☆
106			Fibonacci Number	LeetCode	★☆☆☆☆
107		Recursion on Arrays & Math	Reverse an array	GeeksForGeeks	★★☆☆☆
108			Pow(x, n)	LeetCode	★★☆☆☆
109			Count Good Numbers	LeetCode	★★☆☆☆
110			Recursive Implementation of atoi()	GeeksForGeeks	★★★☆☆
111		Recursion On strings	Generate Binary Strings Without Consecutive 1s	LeetCode	★★★☆☆
✓ Recursion completed — 10 questions
112	Sorting	Sorting Fundamentals	Linear Search	GeeksForGeeks	★☆☆☆☆
113			Sort An Array (Implement Merge / Quick Sort)	LeetCode	★★☆☆☆
114			Sort Array By Parity	LeetCode	★★☆☆☆
115			Maximum Gap	LeetCode	★★★☆☆
116		Custom Comparator Sorting	Sort Elements by Decreasing Frequency	GeeksForGeeks	★★★☆☆
117		Custom Comparator Sorting	Reorder Data In Log Files	LeetCode	★★★★☆
118		Advanced Sorting	Merge Intervals	LeetCode	★★★☆☆
119			Count Inversions (Merge Sort)	GeeksForGeeks	★★★★★
120			Reverse Pairs (Merge Sort)	LeetCode	★★★★★
✓ Sorting completed — 9 questions

PHASE 4 : OBJECT ORIENTED CONCEPTS6 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
121	OOPS	OOPS Fundamentals	Classes, Objects & Constructors	Learn	★☆☆☆☆
122			Inheritance & Polymorphism	Learn	★★☆☆☆
123			Encapsulation & Abstraction	Learn	★★☆☆☆
124			Interfaces & Abstract Classes	Learn	★★★☆☆
125		Design Patterns	Singleton Pattern	Learn	★★★☆☆
126		Design Patterns	Factory Pattern	Learn	★★★★☆
✓ OOPS completed — 6 questions

PHASE 5 : ADVANCED LINEAR DATA STRUCTURES81 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
127	Linkedlist	Foundation	Array to Linked List	GeeksForGeeks	★☆☆☆☆
128			Count Nodes / Find Length of Linked List	GeeksForGeeks	★☆☆☆☆
129			Search in a Linked List	GeeksForGeeks	★☆☆☆☆
130		Insertion and Deletion	Insert Node at Head / Tail	HackerRank	★★☆☆☆
131			Insert in Middle of Linked List	GeeksForGeeks	★★☆☆☆
132			Remove Linked List Elements (By Value)	LeetCode	★★☆☆☆
133			Remove Duplicates from Sorted List	LeetCode	★★☆☆☆
134			Delete Node in a Linked List (Given only node ref)	LeetCode	★★★☆☆
135			Remove Duplicates from Unsorted List	LeetCode	★★★☆☆
136			Delete the Middle Node of a Linked List	LeetCode	★★★☆☆
137		Fast and Slow Pointer	Middle of the Linked List	LeetCode	★★☆☆☆
138			Linked List Cycle	LeetCode	★★☆☆☆
139			Intersection of Two Linked Lists	LeetCode	★★☆☆☆
140			Length of Loop in Linked List	GeeksForGeeks	★★★☆☆
141			Linked List Cycle II (Find Starting Point)	LeetCode	★★★☆☆
142			Remove Loop in Linked List	GeeksForGeeks	★★★☆☆
143			Remove Nth Node From End of List	LeetCode	★★★☆☆
144		Reversals and Rotations	Reverse a Linked List (Iterative & Recursive)	LeetCode	★★☆☆☆
145			Palindrome Linked List	LeetCode	★★☆☆☆
146			Swap Nodes in Pairs	LeetCode	★★★☆☆
147			Odd Even Linked List (By Index)	LeetCode	★★★☆☆
148			Reorder List	LeetCode	★★★★☆
149			Rotate List	LeetCode	★★★★☆
150		Math in Linked List	Add One to a Number Represented by LL	GeeksForGeeks	★★★☆☆
151			Add Two Numbers (Reverse Order)	LeetCode	★★★☆☆
152			Add Two Numbers II (Forward Order)	LeetCode	★★★★☆
153		Sorting, Merging & Segregating	Merge Two Sorted Lists	LeetCode	★★☆☆☆
154			Sort a Linked List of 0s, 1s, and 2s	GeeksForGeeks	★★★☆☆
155			Segregate Even and Odd Nodes (By Value)	GeeksForGeeks	★★★☆☆
156			Partition List	LeetCode	★★★★☆
157			Insertion Sort List	LeetCode	★★★★☆
158			Sort List (Merge Sort on LL)	LeetCode	★★★★★
159		Doubly Linked Lists (DLL)	Array to Doubly Linked List	GeeksForGeeks	★☆☆☆☆
160			Insert/Delete in a Doubly Linked List	Practice	★★☆☆☆
161			Reverse a Doubly Linked List	GeeksForGeeks	★★☆☆☆
162			Remove Duplicates from Sorted DLL	GeeksForGeeks	★★☆☆☆
163			Insert in Sorted way in a Sorted DLL	GeeksForGeeks	★★★☆☆
164			Delete all occurrences of a key in DLL	GeeksForGeeks	★★★☆☆
165			Find Pairs with Given Sum in a DLL	GeeksForGeeks	★★★☆☆
166		Advanced Problems	Copy List with Random Pointer (Clone LL)	LeetCode	★★★★☆
167			Flattening a Linked List	GeeksForGeeks	★★★★☆
168			Reverse Linked List in Groups of Size K	LeetCode	★★★★★
169			Reverse Alternate K Nodes	LeetCode	★★★★★
✓ Linkedlist completed — 43 questions
170	Stacks	Core Implementation	Implement Stack using Arrays	GeeksForGeeks	★☆☆☆☆
171		Core Implementation	Implement Stack using Linked List	GeeksForGeeks	★☆☆☆☆
172		Parentheses & String Parsing	Valid Parentheses	LeetCode	★★☆☆☆
173			Remove Outermost Parentheses	LeetCode	★★☆☆☆
174			Remove All Adjacent Duplicates In String	LeetCode	★★☆☆☆
175			Minimum Add to Make Parentheses Valid	LeetCode	★★☆☆☆
176			Minimum Remove to Make Valid Parentheses	LeetCode	★★★☆☆
177			Evaluate Reverse Polish Notation	LeetCode	★★★☆☆
178		Recursion Based Stack Problems	Sort a Stack Using Recursion	GeeksForGeeks	★★★☆☆
179		Recursion Based Stack Problems	Reverse a Stack (Using Recursion)	GeeksForGeeks	★★★☆☆
180		Expression Conversions	Infix to Postfix Conversion	GeeksForGeeks	★★☆☆☆
181			Prefix to Infix Conversion	GeeksForGeeks	★★☆☆☆
182			Postfix to Prefix Conversion	GeeksForGeeks	★★☆☆☆
183			Infix to Prefix Conversion	GeeksForGeeks	★★★☆☆
184		The Monotonic Stack Pattern	Next Greater Element I	LeetCode	★★☆☆☆
185			Next Smaller Element / Help Classmates	GeeksForGeeks	★★★☆☆
186			Next Greater Element II (Circular Array)	LeetCode	★★★☆☆
187			Stock Span Problem	LeetCode	★★★☆☆
188			Number of Greater Elements to the Right	GeeksForGeeks	★★★☆☆
189			Asteroid Collision	LeetCode	★★★☆☆
190			Remove K Digits	LeetCode	★★★★☆
191			Remove Duplicate Letters	LeetCode	★★★★☆
192		Advanced Monotonic Stack & Applications	Largest Rectangle in Histogram	LeetCode	★★★★☆
193			Sum of Subarray Minimums	LeetCode	★★★★☆
194			Sum of Subarray Ranges	LeetCode	★★★★☆
195			Maximal Rectangle (2D Grid)	LeetCode	★★★★★
196		Classic Design Problems	Min Stack (Design a stack with O(1) getMin)	LeetCode	★★★☆☆
197		Classic Design Problems	The Celebrity Problem (Elimination via Stack)	GeeksForGeeks	★★★☆☆
✓ Stacks completed — 28 questions
198	Queues	Queue Implementation	Implement Queue using Arrays	GeeksForGeeks	★☆☆☆☆
199			Implement Queue using Linked List	GeeksForGeeks	★☆☆☆☆
200			Implement Queue using Stacks	LeetCode	★★☆☆☆
201			Implement Stack using Queues	LeetCode	★★☆☆☆
202			Reverse First K elements of Queue	GeeksForGeeks	★★☆☆☆
203		Queue Applications	Number of Students Unable to Eat Lunch	LeetCode	★★☆☆☆
204		Queue Applications	First non-repeating character in a stream	LeetCode	★★★☆☆
205		Deque & Sliding Window Max	Sliding Window Maximum	LeetCode	★★★★☆
206			Longest Continuous Subarray With Abs Diff ≤ Limit	LeetCode	★★★★☆
207			Constrained Subsequence Sum	LeetCode	★★★★★
✓ Queues completed — 10 questions

PHASE 6 - HIERARCHIAL DATA STRUCTURES57 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
208	Binary Trees	Traversals & Views (Fundamentals)	Preorder Traversal (Recursive & Iterative)	LeetCode	★★★☆☆
209			Inorder Traversal (Recursive & Iterative)	LeetCode	★★★☆☆
210			Postorder Traversal (Recursive & Iterative)	LeetCode	★★★☆☆
211			Binary Tree Level Order Traversal	LeetCode	★★★★☆
212			Binary Tree Zigzag Level Order Traversal	LeetCode	★★★★☆
213			Left / Right View of Binary Tree	LeetCode	★★★★☆
214			Top / Bottom View of Binary Tree	GeeksForGeeks	★★★★☆
215			Boundary Traversal of Binary Tree	GeeksForGeeks	★★★★☆
216			Diagonal Traversal of Binary Tree	GeeksForGeeks	★★★★☆
217			Vertical Order Traversal of a Binary Tree	LeetCode	★★★★★
218		Tree Properties & Dimensions	Maximum Depth of Binary Tree	LeetCode	★★★☆☆
219			Same Tree	LeetCode	★★★☆☆
220			Invert Binary Tree	LeetCode	★★★☆☆
221			Symmetric Tree	LeetCode	★★★★☆
222			Maximum Width of Binary Tree	LeetCode	★★★★☆
223			Count Complete Tree Nodes	LeetCode	★★★★☆
224			Diameter of Binary Tree	LeetCode	★★★★★
225			Balanced Binary Tree	LeetCode	★★★★★
226		Paths, Sums & LCA	Path Sum I	LeetCode	★★★☆☆
227			Path Sum II	LeetCode	★★★★☆
228			Sum Root to Leaf Numbers	LeetCode	★★★★☆
229			Maximum Difference Between Node and Ancestor	LeetCode	★★★★☆
230			Lowest Common Ancestor of a Binary Tree	LeetCode	★★★★★
231			Binary Tree Maximum Path Sum	LeetCode	★★★★★
232			Path Sum III	LeetCode	★★★★★
233		Graph-Like Traversals in Trees	Minimum time taken to burn the BT	GeeksForGeeks	★★★★☆
234			All Nodes Distance K in Binary Tree	LeetCode	★★★★★
235			Step-By-Step Directions From a Binary Tree Node to Another	LeetCode	★★★★★
236		Structural Modifications & Construction	Merge Two Binary Trees	LeetCode	★★★☆☆
237			Children Sum Property in a Binary Tree	GeeksForGeeks	★★★☆☆
238			Construct Binary Tree from Preorder and Inorder Traversal	LeetCode	★★★★★
239			Construct Binary Tree from Inorder and Postorder Traversal	LeetCode	★★★★☆
240			Flatten Binary Tree to Linked List	LeetCode	★★★★☆
241			Serialize and Deserialize Binary Tree	LeetCode	★★★★★
✓ Binary Trees completed — 34 questions
242	Binary Search Trees	Core Properties & Search	Search in a Binary Search Tree	LeetCode	★★☆☆☆
243			Find Minimum/Maximum in BST	GeeksForGeeks	★★☆☆☆
244			Insert into a Binary Search Tree	LeetCode	★★★☆☆
245			Floor and Ceil in a BST	GeeksForGeeks	★★★☆☆
246			Inorder Successor in BST	GeeksForGeeks	★★★★☆
247			Lowest Common Ancestor of a Binary Search Tree	LeetCode	★★★★☆
248			Validate Binary Search Tree	LeetCode	★★★★★
249			Kth Smallest Element in a BST	LeetCode	★★★★★
250		Standard Modifications & Deletions	Delete Node in a BST	LeetCode	★★★★☆
251		Standard Modifications & Deletions	Two Sum IV - Input is a BST	LeetCode	★★★★★
252		Construction & Advanced Operations	Convert Sorted Array to Binary Search Tree	LeetCode	★★★☆☆
253			Construct BST from Preorder Traversal	LeetCode	★★★★☆
254			Balance a Binary Search Tree	LeetCode	★★★★☆
255			Merge Two Balanced Binary Search Trees	GeeksForGeeks	★★★★☆
256			Recover Binary Search Tree	LeetCode	★★★★★
257			Largest BST in a Binary Tree	LeetCode	★★★★★
✓ Binary Search Trees completed — 16 questions
258	Tries	Implementation & String Search	Implement Trie (Prefix Tree)	LeetCode	★★★★☆
259			Design Add and Search Words Data Structure	LeetCode	★★★★☆
260			Longest Word with All Prefixes	GeeksForGeeks	★★★★☆
261			Number of Distinct Substrings in a String	GeeksForGeeks	★★★★☆
262			Word Search II	LeetCode	★★★★★
263		Bitwise Tries (Advanced)	Maximum XOR of Two Numbers in an Array	LeetCode	★★★★★
264		Bitwise Tries (Advanced)	Maximum XOR With an Element From Array	LeetCode	★★★★★
✓ Tries completed — 7 questions

PHASE 7 : CORE DATA STRUCTURES AND TECHNIQUES84 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
265	Hashmaps	Hashmap Fundamentals	Contains Duplicate	LeetCode	★☆☆☆☆
266			Valid Anagram (Hashmap Approach)	LeetCode	★☆☆☆☆
267			Unique Number of Occurrences	LeetCode	★☆☆☆☆
268			Find distinct elements / Find the Frequency	GeeksForGeeks	★☆☆☆☆
269			Two Sum	LeetCode	★★☆☆☆
270			Intersection of Two Arrays	LeetCode	★★☆☆☆
271			Count Number of Pairs With Absolute Difference K	LeetCode	★★☆☆☆
272			Design HashMap	LeetCode	★★★☆☆
273		Intermediate Hashmap Problems	Group Anagrams	LeetCode	★★★☆☆
274			Longest Consecutive Sequence	LeetCode	★★★☆☆
275			Subarray Sum Equals K	LeetCode	★★★☆☆
276			Contiguous Array / Largest subarray with 0 sum	LeetCode	★★★☆☆
277			Count subarrays with given XOR	GeeksForGeeks	★★★☆☆
278			Subarray Sums Divisible by K	LeetCode	★★★☆☆
279			Continuous Subarray Sum	LeetCode	★★★☆☆
280		Advanced / Multi Concept	Maximum Size Subarray Sum Equals k	GeeksForGeeks	★★★☆☆
281			Top K Frequent Elements	LeetCode	★★★☆☆
282			LRU Cache (Least Recently Used)	LeetCode	★★★★☆
283			LFU Cache (Least Frequently Used)	LeetCode	★★★★★
✓ Hashmaps completed — 19 questions
284	Heaps / Priority Queues	Heap Fundamentals	Check if an array represents a min heap	GeeksForGeeks	★★☆☆☆
285			Convert Min Heap to Max Heap	GeeksForGeeks	★★☆☆☆
286			Implement Min/Max Heap	Practice	★★★☆☆
287		The Top-K Pattern	Last Stone Weight	LeetCode	★★★☆☆
288			Kth Largest Element in an Array	LeetCode	★★★★☆
289			K Closest Points to Origin	LeetCode	★★★★☆
290			Sort a K Sorted Array / Nearly Sorted Algorithm	GeeksForGeeks	★★★★☆
291			Top K Frequent Elements (Heap Approach)	LeetCode	★★★★☆
292		Merging & Combinations	Minimum Cost of Ropes	GeeksForGeeks	★★★★☆
293			Merge K Sorted Lists	LeetCode	★★★★★
294			Kth Smallest Element in a Sorted Matrix	LeetCode	★★★★☆
295		Advanced / Two-Heaps / Scheduling	Task Scheduler	LeetCode	★★★★★
296			Reorganize String	LeetCode	★★★★★
297			Minimum Number of Refueling Stops	LeetCode	★★★★★
298			Find Median from Data Stream	LeetCode	★★★★★
✓ Heaps / Priority Queues completed — 15 questions
299	Prefix Sum	1d Prefix Sum	Running Sum of 1D Array	LeetCode	★☆☆☆☆
300			Find the Highest Altitude	LeetCode	★★☆☆☆
301			Find Pivot Index	LeetCode	★★☆☆☆
302			Range Sum Query - Immutable	LeetCode	★★☆☆☆
303			Product of Array Except Self	LeetCode	★★★☆☆
304			Corporate Flight Bookings	LeetCode	★★★★☆
305			Trapping Rain Water (Prefix Max / Min)	LeetCode	★★★★☆
306		2d Prefix Sum	Range Sum Query 2D - Immutable	LeetCode	★★★☆☆
307			Matrix Block Sum	LeetCode	★★★☆☆
308			Maximum Sum of a 2D Subgrid of size K x K	GeeksForGeeks	★★★★☆
✓ Prefix Sum completed — 10 questions
309	Two Pointers & Sliding Window	Two Pointers Basics	Move Zeroes (Two Pointer Intution)	LeetCode	★☆☆☆☆
310			Valid Palindrome (Two Pointers)	LeetCode	★☆☆☆☆
311			Two Sum II - Input Array Is Sorted	LeetCode	★★☆☆☆
312			Sort Colors (Dutch National Flag)	LeetCode	★★☆☆☆
313			Container With Most Water	LeetCode	★★★☆☆
314			3Sum	LeetCode	★★★☆☆
315		Fixed Size Slding Window	Maximum Average Subarray I	LeetCode	★★☆☆☆
316			Max Sum Subarray of size K	LeetCode	★★☆☆☆
317			Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold	LeetCode	★★☆☆☆
318			Minimum Consecutive Cards to Pick Up	LeetCode	★★☆☆☆
319			Maximum Points You Can Obtain from Cards	LeetCode	★★★☆☆
320		Variable Size Sliding Window	Find All Anagrams in a String	LeetCode	★★★☆☆
321			Permutation in String	LeetCode	★★★☆☆
322			Minimum Size Subarray Sum	LeetCode	★★★☆☆
323			Longest Substring Without Repeating Characters	LeetCode	★★★☆☆
324			Longest Repeating Character Replacement	LeetCode	★★★☆☆
325			Max Consecutive Ones III	LeetCode	★★★☆☆
326			Fruit Into Baskets	LeetCode	★★★☆☆
327			Maximum Erasure Value	LeetCode	★★★☆☆
328			Number of Substrings Containing All Three Characters	LeetCode	★★★☆☆
329		Advanced Sliding Window / Counting / Atmost K	Binary Subarrays With Sum	LeetCode	★★★☆☆
330			Count Number of Nice Subarrays	LeetCode	★★★☆☆
331			Subarrays with K Different Integers	LeetCode	★★★★☆
332			Minimum Window Subsequence	LeetCode	★★★★☆
333			Minimum Window Substring	LeetCode	★★★★★
✓ Two Pointers & Sliding Window completed — 25 questions
334	Bit Manipulation	Bit Basics & Properties	K-th Bit is Set or Not	GeeksForGeeks	★☆☆☆☆
335			Check if a Number is Odd or Not	GeeksForGeeks	★☆☆☆☆
336			Check If Number Power of 2 or Not	LeetCode	★★☆☆☆
337			Number Of Even and Odd Bits	LeetCode	★★☆☆☆
338			Minimum Bit Flips To Convert Number	LeetCode	★★★☆☆
339		XOR Tricks	Swap Two Numbers (XOR Trick)	GeeksForGeeks	★★☆☆☆
340			Single Number I	LeetCode	★★☆☆☆
341			Is Binary Number Multiple of 3	GeeksForGeeks	★★☆☆☆
342			Find the repeating and missing number	LeetCode	★★★☆☆
343			Single Number II	LeetCode	★★★★☆
344			Single Number III	LeetCode	★★★★★
345		Bit Counting & Advanced	Count Set Bits From 1 to N	GeeksForGeeks	★★★★☆
346			Bleak Numbers	GeeksForGeeks	★★★★☆
347			Minimum Xor Pair	GeeksForGeeks	★★★★☆
348			Divide Two Integers (Bit Shifting)	LeetCode	★★★★☆
✓ Bit Manipulation completed — 15 questions

PHASE 8 : STANDARD ALGORITHMS77 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
349	Greedy	Basics & Array Manipulation	Assign Cookies	LeetCode	★☆☆☆☆
350			Lemonade Change	LeetCode	★★☆☆☆
351			Maximize Sum of Array After K Negations	LeetCode	★★☆☆☆
352			Shortest Job First	GeeksForGeeks	★★☆☆☆
353			Activity Selection / N Meetings in One Room	GeeksForGeeks	★★☆☆☆
354		Intervals & Scheduling	Merge Intervals (Greedy View)	LeetCode	★★★☆☆
355			Insert Interval	LeetCode	★★★☆☆
356			Non-overlapping Intervals	LeetCode	★★★☆☆
357			Minimum Number of Arrows to Burst Balloons	LeetCode	★★★☆☆
358			Job Sequencing Problem	GeeksForGeeks	★★★☆☆
359			Minimum Platforms required for a railway	GeeksForGeeks	★★★☆☆
360			Maximum Meetings in One Room	GeeksForGeeks	★★★☆☆
361			Task Scheduler (Greedy Approach)	LeetCode	★★★☆☆
362		Array & Jump Greedy	Jump Game	LeetCode	★★★☆☆
363			Valid Parenthesis String	LeetCode	★★★☆☆
364			Gas Station	LeetCode	★★★☆☆
365			Jump Game II	LeetCode	★★★☆☆
366		Advanced Greedy	Minimize the Heights II	GeeksForGeeks	★★★★☆
367			Candy	LeetCode	★★★★☆
368			Huffman Decoding / Coding	GeeksForGeeks	★★★★☆
369			Minimum Number of Taps to Open to Water a Garden	LeetCode	★★★★☆
370			Course Schedule III	LeetCode	★★★★★
✓ Greedy completed — 22 questions
371	Graphs	Graphs Fundamentals & Traversals	BFS of Graph	GeeksForGeeks	★☆☆☆☆
372			DFS of Graph	GeeksForGeeks	★☆☆☆☆
373			Find if Path Exists in Graph	LeetCode	★★☆☆☆
374			Number of Provinces	LeetCode	★★☆☆☆
375			Clone Graph	LeetCode	★★★☆☆
376			Is Graph Bipartite?	LeetCode	★★★☆☆
377		Matrix / Grid BFS Problems	Flood Fill	LeetCode	★★☆☆☆
378			Max Area of Island	LeetCode	★★☆☆☆
379			Number of Islands	LeetCode	★★★☆☆
380			Rotting Oranges	LeetCode	★★★☆☆
381			01 Matrix / Distance of nearest cell having 1	GeeksForGeeks	★★★☆☆
382			Surrounded Regions	LeetCode	★★★☆☆
383			Number of Enclaves	LeetCode	★★★☆☆
384			Shortest Path in Binary Matrix	LeetCode	★★★☆☆
385			Swim in Rising Water	LeetCode	★★★★☆
386			Making A Large Island	LeetCode	★★★★☆
387		Cycle Detection	Cycle Detection in Undirected Graph	GeeksForGeeks	★★☆☆☆
388			Detect Cycle in a Directed Graph	GeeksForGeeks	★★★☆☆
389			Find Eventual Safe States	LeetCode	★★★☆☆
390		Topological Sorting (Kahn's Algorithm)	Topological Sort	GeeksForGeeks	★★☆☆☆
391			Course Schedule	LeetCode	★★★☆☆
392			Course Schedule II	LeetCode	★★★☆☆
393			Alien Dictionary	GeeksForGeeks	★★★★☆
394			Parallel Courses III	LeetCode	★★★★☆
395		Shortest Path Algorithms (Dijkstra, Bellman-Ford, Floyd-Warshall)	Shortest Path in Undirected Graph (Unit Weights)	GeeksForGeeks	★★☆☆☆
396			Shortest Path in DAG	GeeksForGeeks	★★☆☆☆
397			Dijkstra's Algorithm	GeeksForGeeks	★★★☆☆
398			Network Delay Time	LeetCode	★★★☆☆
399			Path With Minimum Effort	LeetCode	★★★☆☆
400			Cheapest Flights Within K Stops	LeetCode	★★★☆☆
401			Path with Maximum Probability	LeetCode	★★★☆☆
402			Bellman-Ford Algorithm	GeeksForGeeks	★★★☆☆
403			Floyd Warshall Algorithm	GeeksForGeeks	★★★☆☆
404			Find the City With the Smallest Number of Neighbors	LeetCode	★★★☆☆
405			Minimum Multiplications to Reach End	GeeksForGeeks	★★★☆☆
406			Number of Ways to Arrive at Destination	LeetCode	★★★☆☆
407		Minimum Spanning Tree (MST)	Minimum Spanning Tree	GeeksForGeeks	★★☆☆☆
408			Prim's Algorithm	GeeksForGeeks	★★★☆☆
409			Min Cost to Connect All Points (Kruskal)	LeetCode	★★★☆☆
410		Disjoint Set Union (DSU) / Union Find	Disjoint Set	GeeksForGeeks	★★☆☆☆
411			Number of Operations to Make Network Connected	LeetCode	★★★☆☆
412			Accounts Merge	LeetCode	★★★☆☆
413			Most Stones Removed with Same Row or Column	LeetCode	★★★☆☆
414			Redundant Connection	LeetCode	★★★☆☆
415			Evaluate Division	LeetCode	★★★★☆
416			Number of Islands II	LeetCode	★★★★☆
417		Bridges, Articulation Points & Strongly Connected Components	Kosaraju's Algorithm	Practice	★★★★☆
418			Tarjan's Algorithm / Bridges in Graph	GeeksForGeeks	★★★★☆
419			Articulation Point in Graph	GeeksForGeeks	★★★★☆
420			Critical Connections in a Network	LeetCode	★★★★☆
421		Advanced Graphs Problems	Snake and Ladder Problem	LeetCode	★★★☆☆
422			Word Ladder	LeetCode	★★★★☆
423			Reorder Routes to Make All Paths Lead to the City Zero	LeetCode	★★★★☆
424			Word Ladder II	LeetCode	★★★★★
425			Escape the Spreading Fire	LeetCode	★★★★★
✓ Graphs completed — 55 questions

PHASE 9 : EXHAUSTIVE SEARCH & OPTIMISATION77 questions

#	Topic	Subtopic	Problem Name	Link	Difficulty
426	Backtracking	Subsequence & Subset Fundamentals	Check if subsequence with sum K Exists	GeeksForGeeks	★★☆☆☆
427			Count all subsequences with sum K	Practice	★★☆☆☆
428			Subsets / Power Set	LeetCode	★★★☆☆
429			Subsets II (With Duplicates)	LeetCode	★★★☆☆
430			Subset Sums	GeeksForGeeks	★★★☆☆
431		Combinations	Combination Sum I	LeetCode	★★★☆☆
432			Combination Sum II	LeetCode	★★★☆☆
433			Combination Sum III	LeetCode	★★★☆☆
434			N Digit numbers with digits in increasing order	GeeksForGeeks	★★★☆☆
435		Permutations	Permutations II (With Duplicates)	LeetCode	★★★☆☆
436			Letter Combinations of a Phone Number	LeetCode	★★★☆☆
437			Generate Parentheses	LeetCode	★★★☆☆
438		String BackTracking	Palindrome Partitioning	LeetCode	★★★★☆
439			Word Break	LeetCode	★★★★☆
440			Remove Invalid Parentheses	LeetCode	★★★★★
441			Expression Add Operators	LeetCode	★★★★★
442		Grid & Maze Backtracking	Rat in a Maze	GeeksForGeeks	★★★★☆
443			Word Search	LeetCode	★★★★☆
444			M-Coloring Problem	GeeksForGeeks	★★★★☆
445			N-Queens	LeetCode	★★★★★
446			N-Queens II	LeetCode	★★★★★
447			Sudoku Solver	LeetCode	★★★★★
✓ Backtracking completed — 22 questions
448	Dynamic Programming	1D DP (Intro to State & Transitions)	Fibonacci Number	LeetCode	★☆☆☆☆
449			Climbing Stairs	LeetCode	★☆☆☆☆
450			Min Cost Climbing Stairs	LeetCode	★★☆☆☆
451			Frog Jump	LeetCode	★★☆☆☆
452			Frog Jump with K Distances	LeetCode	★★☆☆☆
453			House Robber	LeetCode	★★☆☆☆
454			House Robber II	LeetCode	★★★☆☆
455			Decode Ways	LeetCode	★★★☆☆
456		2D Grids & Paths	Unique Paths	LeetCode	★★☆☆☆
457			Unique Paths II	LeetCode	★★★☆☆
458			Minimum Path Sum	LeetCode	★★★☆☆
459			Triangle	LeetCode	★★★☆☆
460			Minimum Falling Path Sum	LeetCode	★★★☆☆
461			Dungeon Game	LeetCode	★★★★☆
462			Cherry Pickup II / Ninja and his Friends	LeetCode	★★★★☆
463		0/1 Knapsack & Subsets	Subset Sum Problem	GeeksForGeeks	★★☆☆☆
464			Partition Equal Subset Sum	LeetCode	★★★☆☆
465			Count Subsets with Sum K	Practice	★★★☆☆
466			Target Sum	GeeksForGeeks	★★★☆☆
467			Count Partitions with Given Difference	GeeksForGeeks	★★★☆☆
468			0/1 Knapsack Problem	GeeksForGeeks	★★★☆☆
469			Partition Array Into Two Arrays to Minimize Sum Difference	LeetCode	★★★★☆
470			Last Stone Weight II	LeetCode	★★★★☆
471		Unbounded Knapsack	Rod Cutting Problem	GeeksForGeeks	★★★☆☆
472			Coin Change	LeetCode	★★★☆☆
473			Coin Change II	LeetCode	★★★☆☆
474			Perfect Squares	LeetCode	★★★☆☆
475		DP on Strings (LCS & Edit Distance Patterns)	Longest Common Subsequence	LeetCode	★★★☆☆
476			Print Longest Common Subsequence	GeeksForGeeks	★★★☆☆
477			Longest Common Substring	GeeksForGeeks	★★★☆☆
478			Longest Palindromic Subsequence	LeetCode	★★★☆☆
479			Minimum Insertions to Make String Palindrome	LeetCode	★★★☆☆
480			Delete Operation for Two Strings	LeetCode	★★★☆☆
481			Shortest Common Supersequence	LeetCode	★★★★☆
482			Distinct Subsequences	LeetCode	★★★★☆
483			Edit Distance	LeetCode	★★★★☆
484			Wildcard Matching	LeetCode	★★★★☆
485			Regular Expression Matching	LeetCode	★★★★★
486		DP on Stocks	Best Time to Buy and Sell Stock	LeetCode	★☆☆☆☆
487			Best Time to Buy and Sell Stock II	LeetCode	★★☆☆☆
488			Best Time to Buy and Sell Stock with Cooldown	LeetCode	★★☆☆☆
489			Best Time to Buy and Sell Stock with Transaction Fee	LeetCode	★★★☆☆
490			Best Time to Buy and Sell Stock III	LeetCode	★★★★☆
491			Best Time to Buy and Sell Stock IV	LeetCode	★★★★☆
492		Longest Increasing Subsequence (LIS)	Longest Increasing Subsequence	LeetCode	★★★☆☆
493			Print Longest Increasing Subsequence	GeeksForGeeks	★★★☆☆
494			Largest Divisible Subset	LeetCode	★★★☆☆
495			Longest String Chain	LeetCode	★★★☆☆
496			Longest Bitonic Subsequence	GeeksForGeeks	★★★★☆
497			Number of Longest Increasing Subsequences	LeetCode	★★★★☆
498			Russian Doll Envelopes	LeetCode	★★★★★
499		Partition DP & Matrix Chain Multiplication (MCM)	Matrix Chain Multiplication	GeeksForGeeks	★★★★☆
500			Minimum Cost to Cut a Stick	LeetCode	★★★★☆
501			Burst Balloons	LeetCode	★★★★★
502			Palindrome Partitioning II	LeetCode	★★★★★
✓ Dynamic Programming completed — 55 questions

📑 DSA Master Sheet