POTD Solutions

GeeksforGeeks Java Solutions

Daily Problem of the Day solutions — clean Java code with explanations and complexity analysis for every GFG POTD.

565

Solved

565 problemsFull explanation available

#	Title
1	0 - 1 Knapsack Problem
2	2D Difference Array
3	2D Submatrix Sum Queries
4	Activity Selection
5	Add 1 to a Linked List Number
6	Add Binary Strings
7	Add Number Linked Lists
8	Aggressive Cows
9	Alien Dictionary
10	All numbers with specific difference
11	All Subsets Xor Sum
12	All Unique Permutations of an array
13	Allocate Minimum Pages
14	Alternate positive and negative numbers
15	Alternative Sorting
16	Anagram
17	Anagram Palindrome
18	Ancestors in Binary Tree
19	AND In Range
20	Array Duplicates
21	Array to BST
22	Articulation Point - II
23	ASCII Range Sum
24	Assign Mice Holes
25	Balancing Consonants and Vowels Ratio
26	Bellman-Ford
27	BFS of graph
28	Binary Tree to DLL
29	Bitonic Point
30	Boolean Parenthesization
31	Bottom View of Binary Tree
32	Brackets in Matrix Chain Multiplication
33	Bridge edge in a graph
34	BST to greater sum tree
35	BST with Dead End
36	Buildings with Sunlight
37	Burning Tree
38	Bus Conductor
39	Bus Ticket Change
40	Buy Stock with Transaction Fee
41	Candy
42	Case-specific Sorting of Strings
43	Check for BST
44	Check for Power
45	Check if a String is Subsequence of Other
46	Check if an Array is Max Heap
47	Check if frequencies can be equal
48	Check If two Line segments Intersect
49	Chocolate Distribution Problem
50	Chocolate Pickup II
51	Chocolates Pickup
52	Circle of strings
53	Clone a linked list with next and random pointer
54	Clone an Undirected Graph
55	Clone List with Next and Random
56	Closest Neighbour in BST
57	Closest Three Sum
58	Coin Change (Count Ways)
59	Coin Change (Minimum Coins)
60	Coin Piles
61	Common in 3 Sorted Arrays
62	Compare two fractions
63	Consecutive 1's not allowed
64	Construct an array from its pair-sum array
65	Construct Binary Tree from Parent Array
66	Construct Tree from Inorder & Preorder
67	Construct Tree from Preorder & Postorder
68	Container With Most Water
69	Count all triplets with given sum in sorted array
70	Count Derangements
71	Count distinct elements in every window
72	Count elements less than or equal to k in a sorted rotated array
73	Count increasing Subarrays
74	Count Indices to Balance Even and Odd Sums
75	Count Inversions
76	Count Linked List Nodes
77	Count Numbers Containing Specific Digits
78	Count of distinct substrings
79	Count pairs Sum in matrices
80	Count Pairs whose sum is less than target
81	Count pairs with given sum
82	Count Reverse Pairs
83	Count set bits
84	Count Smaller elements
85	Count Subarray with k odds
86	Count Subarrays with given XOR
87	Count Subset With Target Sum II
88	Count the Coprimes
89	Count the number of possible triangles
90	Count the paths
91	Count Unique Vowel Strings
92	Count ways to N'th Stair(Order does not matter)
93	Count X in Range of a Sorted Array
94	Counting elements in two arrays
95	Course Schedule I
96	Course Schedule II
97	Coverage of all Zeros in a Binary Matrix
98	Cutting Binary String
99	Decode the string
100	Delete Alternate Nodes
101	Delete node in Doubly Linked List
102	Deletion and Reverse in Circular Linked List
103	Design MinMax Queue
104	Detect Loop in linked list
105	DFS of Graph
106	Diameter of a Binary Tree
107	Dice throw
108	Difference Check
109	Dijkstra Algorithm
110	Directed Graph Cycle
111	Distance of nearest cell having 1
112	Distribute Candies
113	Divisible by 13
114	Duplicate Subtrees
115	Edit Distance
116	Elements in range [a, b]
117	Equalize the Towers
118	Equilibrium Point
119	Evaluation of Postfix Expression
120	Exactly one swap
121	Expression Add Operators
122	Expression contains redundant bracket or not
123	Extract the Number from the String
124	Facing the sun
125	Farthest Smaller Right
126	Find all possible palindromic partitions of a String
127	Find All Triplets with Zero Sum
128	Find H-Index
129	Find K Smallest Sum Pairs
130	Find Kth Rotation
131	Find length of Loop
132	Find maximum volume of a cuboid
133	Find median in a stream
134	Find Only Repetitive Element from 1 to n-1
135	Find rectangle with corners as 1
136	Find the closest pair from two arrays
137	Find the first node of loop in linked list
138	Find the longest string
139	Find the number of islands
140	Find the Sum of Last N nodes of the Linked List
141	Fixing Two nodes of a BST
142	Flattening a Linked List
143	Flip to Maximize 1s
144	Flood fill Algorithm
145	Floyd Warshall
146	Form a palindrome
147	Form the Largest Number
148	Frog Jump
149	Game of XOR
150	Game with String
151	Gas Station
152	Generate all binary strings
153	Generate Binary Numbers
154	Generate IP Addresses
155	Generate Permutations of an array
156	Get Min from Stack
157	Get Minimum Squares
158	Gold Mine Problem
159	Graph Diameter
160	Gray Code
161	Group Balls by Sequence
162	Happiest Triplet
163	Height of Binary Tree
164	Histogram Max Rectangular Area
165	Huffman Encoding
166	Identical Linked Lists
167	Implement Atoi
168	Implement k Queues in a Single Array
169	Implement Pow
170	Implement Trie
171	Indexes of Subarray Sum
172	Inorder Traversal
173	Insert in Sorted Circular Linked List
174	Insert in Sorted way in a Sorted DLL
175	Insert Interval
176	Integral Points Inside Triangle
177	Interleave the First Half of the Queue with Second Half
178	Interleaved Strings
179	Intersection in Y Shaped Lists
180	Intersection of Two arrays with Duplicate Elements
181	Intersection of Two Sorted Arrays
182	Intersection Point in Y Shaped Linked Lists
183	Is Binary Tree Heap
184	Is Linked List Length Even
185	Job Sequencing Problem
186	Josephus problem
187	K closest elements
188	K Closest Points to Origin
189	K closest Values
190	k largest elements
191	K Sized Subarray Maximum
192	K Sum Paths
193	K-Pangrams
194	K-th element of two Arrays
195	K-th Largest Sum Contiguous Subarray
196	k-th Smallest in BST
197	Kadane's Algorithm
198	Koko Eating Bananas
199	Kth distance
200	Kth element in Matrix
201	Kth Largest in a Stream
202	Kth Missing Positive Number in a Sorted Array
203	Kth Smallest
204	Kth Smallest Number in Multiplication Table
205	Largest BST
206	Largest Divisible Subset
207	Largest number in K swaps
208	Largest number in one swap
209	Largest Pair Sum
210	Largest square formed in a matrix
211	Largest subarray of 0's and 1's
212	Last Moment Before All Ants Fall Out
213	LCM Triplet
214	LCS of three strings
215	Left Rotate Matrix K times
216	Left View of Binary Tree
217	Length of Longest Cycle in a Graph
218	Level Order in spiral form
219	Level order traversal
220	Lexicographically Largest String After Deleting K Characters
221	Linked List Group Reverse
222	Linked List Matrix
223	Linked list of strings forms a palindrome
224	Longest alternating subsequence
225	Longest Bounded-Difference Subarray
226	Longest Common Increasing Subsequence
227	Longest Common Prefix of Strings
228	Longest Common Subsequence
229	Longest Common Substring
230	Longest Consecutive Subsequence
231	Longest Increasing Subsequence
232	Longest Palindrome in a String
233	Longest Palindromic Subsequence
234	Longest Periodic Proper Prefix
235	Longest Prefix Suffix
236	Longest Repeating Character Replacement
237	Longest Span in two Binary Arrays
238	Longest String Chain
239	Longest Subarray Length
240	Longest subarray with Atmost two distinct integers
241	Longest Subarray with Majority Greater than K
242	Longest Subarray with Sum K
243	Longest substring with distinct characters
244	Longest Substring with K Uniques
245	Longest valid Parentheses
246	Look and Say Pattern
247	Lowest Common Ancestor in a BST
248	LRU Cache
249	Majority Element
250	Majority Element II
251	Majority Vote
252	Make array elements unique
253	Make Binary Tree From Linked List
254	Make Matrix Beautiful
255	Make Strings Equal
256	Matrix Chain Multiplication
257	Max Circular Subarray Sum
258	Max DAG Edges
259	Max distance between same elements
260	Max min Height
261	Max of min for every window size
262	Max rectangle
263	Max Score from Subarray Mins
264	Max sum in the configuration
265	Max Sum Increasing Subsequence
266	Max sum path in two arrays
267	Max Sum Subarray of size K
268	Max Xor Subarray of size K
269	Maximise String Score
270	Maximize Array Value After Rearrangement
271	Maximize median after doing k addition operation
272	Maximize Number of 1's
273	Maximize partitions in a String
274	Maximize The Cut Segments
275	Maximize the minimum difference between k elements
276	Maximum Connected group
277	Maximum Difference
278	Maximum Non-Adjacent Nodes Sum
279	Maximum Non-Overlapping Odd Palindrome Sum
280	Maximum number of overlapping Intervals
281	Maximum of minimum for every window size
282	Maximum path sum
283	Maximum path sum from any node
284	Maximum People Visible in a Line
285	Maximum Product Subarray
286	Maximum product subset of an array
287	Maximum Stone Removal
288	Maximum subarray sum 2
289	Maximum Sum Combination
290	Maximum sum of elements not part of LIS
291	Maximum sum of Non-adjacent nodes
292	Maximum sum Rectangle
293	Maximum XOR of two numbers in an array
294	Mean of range in array
295	Median in a row-wise sorted Matrix
296	Median of BST
297	Median of two sorted arrays
298	Meeting Rooms
299	Meeting Rooms III
300	Merge K sorted linked lists
301	Merge Sort for Linked List
302	Merge two BST 's
303	Merge two sorted linked lists
304	Merge Without Extra Space
305	Middle of a Linked List
306	Min Add to Make Parentheses Valid
307	Min Chars to Add for Palindrome
308	Min Cost Climbing Stairs
309	Min Swaps to Group 1s
310	Minimal Cost
311	Minimize the Heights I
312	Minimize the Heights II
313	Minimum Cost of ropes
314	Minimum Cost Path
315	Minimum cost to connect all houses in a city
316	Minimum Cost to cut a board into squares
317	Minimum Cost to Cut a Stick of length N
318	Minimum Cost to Merge Stones
319	Minimum days to make M bouquets
320	Minimum Deletions
321	Minimum height roots
322	Minimum Jumps
323	Minimum K Consecutive Bit Flips
324	Minimum number of deletions and insertions
325	Minimum Number of Workers
326	Minimum Operations to Connect Hospitals
327	Minimum Platforms
328	Minimum repeat to make substring
329	Minimum Steps to Halve Sum
330	Minimum sum
331	Minimum Weight Cycle
332	Minimum Window Subsequence
333	Mirror Tree
334	Missing And Repeating
335	Missing Element in Range
336	Missing element of AP
337	Missing in Array
338	Mobile numeric keypad
339	Modify the Array
340	Move All Zeroes to End
341	Multiply two linked lists
342	Multiply two strings
343	N meetings in one room
344	N-Queen Problem
345	nCr
346	Nearest multiple of 10
347	Nearly sorted
348	Next element with greater frequency
349	Next Greater Element
350	Next Greater Element in Circular Array
351	Next Permutation
352	Next Smallest Palindrome
353	Nine Divisors
354	Non Repeating Character
355	Non-overlapping Intervals
356	Not a subset sum
357	Nth Natural Number
358	Number of BST From Array
359	Number of distinct subsequences
360	Number of occurrence
361	Number of pairs
362	Number of paths in a matrix with k coins
363	Number of Rectangles in a Circle
364	Number of Ways to Arrive at Destination
365	Occurence of an integer in a Linked List
366	Opposite Sign Pair Reduction
367	Optimal binary search tree
368	Optimal Strategy For A Game
369	Overlapping Intervals
370	Painting the Fence
371	Pair Sum in BST
372	Pair with given sum in a sorted array
373	Pairs with difference k
374	Palindrome Linked List
375	Palindrome Sentence
376	Palindrome SubStrings
377	Parenthesis Checker
378	Partition Equal Subset Sum
379	Partitions with Given Difference
380	Pascal Triangle
381	Path With Minimum Effort
382	Peak element
383	Permutations of a String
384	Police and Thieves
385	Populate Inorder Successor for all nodes
386	Possible Words From Phone Digits
387	Postfix Evaluation
388	Postorder Traversal
389	Power of k in factorial of n
390	Powerful Integer
391	Predecessor and Successor
392	Prime List
393	Prime Pair with Target Sum
394	Print Anagrams Together
395	Print Bracket Number
396	Print Diagonally
397	Print leaf nodes from preorder traversal of BST
398	Product array puzzle
399	Pythagorean Triplet
400	Queue Reversal
401	Quick Sort on Linked List
402	Rat in a Maze
403	Rat in a Maze Problem - I
404	Remaining String
405	Remove all occurences of duplicates in a linked list
406	Remove BST keys outside given range
407	Remove Duplicates
408	Remove duplicates in array
409	Remove Half Nodes
410	Remove loop in Linked List
411	Remove Spaces
412	Remove the balls
413	Reorganize The Array
414	Replace O's with X's
415	Reverse a Doubly Linked List
416	Reverse a linked list
417	Reverse an Array
418	Reverse Words
419	Roman Number to Integer
420	Roof Top
421	Root to leaf path sum
422	Root to Leaf Paths
423	Root to leaf paths sum
424	Rotate a Linked List
425	Rotate and delete
426	Rotate Array
427	Rotate by 90 degree
428	Rotate Deque By K
429	Rotten Oranges
430	Row with max 1s
431	Safe States
432	Search in a Row-Column sorted matrix
433	Search in a row-wise sorted matrix
434	Search in a sorted Matrix
435	Search in an almost Sorted Array
436	Search in fully rotated sorted 2D matrix
437	Search in Rotated Sorted Array
438	Search insert position of K in a sorted array
439	Search Pattern (KMP-Algorithm)
440	Search Pattern (Rabin-Karp Algorithm)
441	Second Best Minimum Spanning Tree
442	Second Largest
443	Segregate 0s and 1s
444	Serialize and deserialize a binary tree
445	Set Matrix Zeroes
446	Set Matrix Zeros
447	Shop in Candy Store
448	Shortest Common Supersequence
449	Shortest Cycle
450	Shortest path in Undirected Graph
451	Shortest Path in Weighted undirected graph
452	Shortest Path Using Atmost One Curved Edge
453	Single Number
454	Size of Binary Tree
455	Smallest distinct window
456	Smallest Divisor
457	Smallest number
458	Smallest Positive Missing
459	Smallest Positive Missing Number
460	Smallest range in K lists
461	Smallest window containing 0, 1 and 2
462	Smallest window containing all characters
463	Smallest window in a string containing all the characters of another string
464	Solve the Sudoku
465	Sort 0s, 1s and 2s
466	Sort a k sorted doubly linked list
467	Sort a linked list of 0s, 1s and 2s
468	Sort by Absolute Difference
469	Sort in specific order
470	Sort the given array after applying the given equation
471	Sorted and Rotated Minimum
472	Sorted subsequence of size 3
473	Sorting Elements of an Array by Frequency
474	Spirally traversing a matrix
475	Split an array into two equal Sum subarrays
476	Split array in three equal sum subarrays
477	Split Array Largest Sum
478	Split Array Subsequences
479	Split Linked List Alternatingly
480	Split the Array
481	Square root of a number
482	Stable Marriage Problem
483	Stickler Thief
484	Stickler Thief II
485	Stock Buy and Sell – Max 2 Transactions Allowed
486	Stock Buy and Sell – Max K Transactions Allowed
487	Stock Buy and Sell – Max one Transaction Allowed
488	Stock Buy and Sell – Multiple Transaction Allowed
489	Stock Buy and Sell with Cooldown
490	Stock span problem
491	Stream First Non-repeating
492	String stack
493	Strings Rotations of Each Other
494	Sub-arrays with equal number of occurences
495	Subarray range with given sum
496	Subarrays With At Most K Distinct Integers
497	Subarrays with First Element Minimum
498	Subarrays with sum K
499	Subset Sum Problem
500	Subset XOR
501	Substrings of length k with k-1 distinct elements
502	Substrings with K Distinct
503	Substrings with same first and last characters
504	Sum of all substrings of a number
505	Sum of Mode
506	Sum of Nodes in BST Range
507	Sum of nodes on the longest path
508	Sum of subarray minimum
509	Sum of subarray minimums
510	Sum of subarray ranges
511	Sum of Subarrays
512	Sum of XOR of all pairs
513	Sum Pair closest to target
514	Sum Tree
515	Sum-string
516	Summed Matrix
517	Swap and Maximize
518	Swap diagonals
519	Swap Kth nodes from ends
520	Symmetric Tree
521	Target Sum
522	The Celebrity Problem
523	The Knight's tour problem
524	The Painter's Partition Problem-II
525	The Palindrome Pattern
526	Toeplitz matrix
527	Top K Frequent in Array
528	Top View of Binary Tree
529	Topological sort
530	Total count
531	Total Decoding Messages
532	Trail of ones
533	Transpose of Matrix
534	Trapping Rain Water
535	Travelling Salesman Problem
536	Tree Boundary Traversal
537	Triplet Family
538	Two Equal Sum Subarrays
539	Two Smallests in Every Subarray
540	Two Sum - Pair with Given Sum
541	Two Swaps
542	Two water Jug problem
543	Tywin's War Strategy
544	Undirected Graph Cycle
545	Union of Arrays with Duplicates
546	Union of Two Sorted Arrays with Distinct Elements
547	Unique K-Number Sum
548	Unique Number I
549	Unique Number II
550	Unique Number III
551	Unique Paths in a Grid
552	URLify a given string
553	Validate an IP Address
554	Vertical Tree Traversal
555	Vertical Width of a Binary Tree
556	Walls Coloring II
557	Ways to Reach the n'th Stair
558	Ways To Tile A Floor
559	Weighted Job Scheduling
560	Wildcard Pattern Matching
561	Word Break
562	Word Search
563	XOR Linked List
564	XOR Pairs less than K
565	ZigZag Tree Traversal