Here Are the Solutions of the POTD & other problems in GFG
Day 1(14 JAN) : Find duplicate rows in a binary matrix
Day 2(15 JAN) : Grinding Geek
Day 3(16 JAN) : Sequence of Sequence
Day 4(17 JAN) : All Unique Permutations of an array
Day 5(18 JAN) : Water the plants
Day 6(19 JAN) : Top k numbers in a stream
Day 7(20 JAN) : Distribute candies in a binary tree
Day 8(21 JAN) : Vertex Cover
Day 9(22 JAN) : Paths from root with a specified sum
Day 10(23 JAN) : Course Schedule
Day 11(24 JAN) : Check if a given graph is tree or not
Day 12(25 JAN) : Shortest Prime Path
Day 13(26 JAN) : Fractional Knapsack
Day 14(27 JAN) : Brackets in Matrix Chain Multiplication
Day 15(28 JAN) : Geekina Hate 1s
Day 16(29 JAN) : Count digit groupings of a number
Day 17(30 JAN) : LCS of three strings
Day 18(31 JAN) : Insert and Search in a Trie
Day 19(1 FEB) : Panagram Checking
Day 20(2 FEB) : Implement Atoi
Day 21(3 FEB) : Decimal Equivalent of Binary Linked List
Day 22(4 FEB) : Subtraction in Linked List
Day 23(5 FEB) : Sorted insert for circular linked list
Day 24(6 FEB) : Node at distance
Day 25(7 FEB) : Min distance between two given nodes of a Binary Tree
Day 26(8 FEB) : Check if all leaves are at same level
Day 27(9 FEB) : Check for Children Sum Property in a Binary Tree
Day 28(10 FEB) : Number of paths in a matrix with k coins
Day 29(11 FEB) : Recamans sequence
Day 30(12 FEB) : Recursive sequence
Day 31(13 FEB) : Clone an Undirected Graph
Day 32(14 FEB) : Find all Critical Connections in the Graph
Day 33(15 FEB) : Count all Possible Path
Day 34(16 FEB) : Flatten BST to sorted list
Day 35(17 FEB) : Does array represent Heap
Day 36(18 FEB) : Sum of leaf nodes in BST
Day 37(19 FEB) : Game with String
Day 38(20 FEB) : Word Break
Day 39(21 FEB) : Boolean Parenthesization
Day 40(22 FEB) : Distinct occurrences
Day 41(23 FEB) : Buy and Sell a Share at most twice
Day 42(24 FEB) : Maximum Sum Problem
Day 43(25 FEB) : Reach a given score
Day 44(26 FEB) : Power Set
Day 45(27 FEB) : Play With OR
Day 46(28 FEB) : Check if a number is divisible by 8
Day 47(29 FEB) : Sum of bit differences
Day 48(03 MAR) : Largest Number formed from an Array
Day 49(04 MAR) : Swap the array elements
Day 50(05 MAR) : Maximum Index
Day 51(06 MAR) : Search Pattern (Rabin-Karp Algorithm)
Day 52(07 MAR) : Longest repeating and non-overlapping substring
Day 53(08 MAR) : Check if frequencies can be equal
Day 54(09 MAR) : Find the N-th character
Day 55(10 MAR) : Remove all duplicates from a given string
Day 56(11 MAR) : Count pairs Sum in matrices
Day 57(12 MAR) : Generalised Fibonacci numbers
Day 58(13 MAR) : Print matrix in diagonal pattern
Day 59(14 MAR) : Largest subsquare surrounded by X
Day 60(15 MAR) : Linked List that is Sorted Alternatingly
Day 61(16 MAR) : Delete without head pointer
Day 62(17 MAR) : Count Pairs whose sum is equal to X
Day 63(18 MAR) : Level order traversal
Day 64(19 MAR) : Possible Paths in a Tree
Day 65(20 MAR) : Sum of nodes on the longest path from root to leaf node
Day 66(21 MAR) : ZigZag Tree Traversal
Day 67(22 MAR) : Diagonal sum in binary tree
Day 68(23 MAR) : Fibonacci series up to Nth term
Day 69(24 MAR) : Insert an Element at the Bottom of a Stack
Day 70(25 MAR) : Print N-bit binary numbers having more 1s than 0s
Day 71(26 MAR) : Additive sequence
Day 72(27 MAR) : Find shortest safe route in a matrix
Day 73(28 MAR) : City With the Smallest Number of Neighbors at a Threshold Distance
Day 74(29 MAR) : Euler Circuit in an Undirected Graph
Day 75(30 MAR) : Minimum element in BST
Day 76(31 MAR) : Closest Neighbour in BST
Day 77(1 APR) : Pairs violating the BST property
Day 78(2 APR) : Minimum Absolute Difference In BST
Day 79(3 APR) : Kth common ancestor in BST
Day 80(4 APR) : Sum of all substrings of a number
Day 81(5 APR) : Strictly Increasing Array
Day 82(6 APR) : Count ways to N'th Stair
Day 83(7 APR) : Maximize dot product
Day 84(8 APR) : Optimal Strategy For A Game
Day 85(9 APR) : Minimum Points To Reach Destination
Day 86(10 APR) : Party of Couples
Day 87(11 APR) : Gray to Binary equivalent
Day 88(12 APR) : Sum of Products
Day 89(13 APR) : Reverse Bits
Day 90(14 APR) : Xoring and Clearing
Day 91(15 APR) : Count the elements
Day 92(16 APR) : Minimize the Difference
Day 93(17 APR) : Count Pairs in an Array
Day 94(18 APR) : Smallest String Starting From Leaf
Day 95(19 APR) : Find missing in second array
Day 96(20 APR) : Union of Two Sorted Arrays
Day 97(21 APR) : Three way partitioning
Day 98(22 APR) : Row with minimum number of 1's
Day 99(23 APR) : Rohan's Love for Matrix
Day 100(24 APR) : Paths to reach origin
Day 101(25 APR) : Maximum sum of hour glass
Day 102(26 APR) : Exit Point in a Matrix
Day 103(27 APR) : Merge Sort on Doubly Linked List
Day 104(28 APR) : Delete Middle of Linked List
Day 105(29 APR) : Remove every kth node
Day 106(30 APR) : Add two numbers represented by linked lists
Day 107(1 MAY) : Arrange Consonants and Vowels
Day 108(2 MAY) : Serialize and deserialize a binary tree
Day 109(3 MAY) : K distance from root
Day 110(4 MAY) : Construct Binary Tree from Inorder and Postorder
Day 111(5 MAY) : Vertical sum
Day 112(6 MAY) : Print all nodes that don't have sibling
Day 113(7 MAY) : Reverse Level Order Traversal
Day 114(8 MAY) : Root to Leaf Paths
Day 115(9 MAY) : Divisor Game
Day 116(10 MAY) : Combination Sum II
Day 117(11 MAY) : Juggler Sequence
Day 118(12 MAY) : Minimum steps to destination
Day 119(13 MAY) : Number of Good Components
Day 120(14 MAY) : Path With Minimum Effort
Day 121(15 MAY) : Account Merge
Day 122(16 MAY) : Divisibility tree
Day 123(17 MAY) : Find Pair Given Difference
Day 124(18 MAY) : Find the Highest number
Day 125(19 MAY) : Find the closest number
Day 126(20 MAY) : Modular Exponentiation for large numbers
Day 127(21 MAY) : K closest elements
Day 128(22 MAY) : Minimize Max Distance to Gas Station
Day 129(23 MAY) : K-Palindrome
Day 130(24 MAY) : Partitions with Given Difference
Day 131(25 MAY) : You and your books
Day 132(26 MAY) : Minimum Cost To Make Two Strings Identical
Day 133(27 MAY) : Longest subsequence-1
Day 134(28 MAY) : Minimum cost to fill given weight in a bag
Day 135(29 MAY) : Geek and its Game of Coins
Day 136(30 MAY) : String Subsequence
Day 137(31 MAY) : Swap two nibbles in a byte
Day 138(1 JUN) : Odd Even Problem
Day 139(2 JUN) : Construct list using given q XOR queries
Day 140(3 JUN) : Trail of ones
Day 141(4 JUN) : Binary representation of next number
Day 142(5 JUN) : Swapping pairs make sum equal
Day 143(6 JUN) : Max sum in the configuration
Day 144(7 JUN) : Maximum occured integer
Day 145(8 JUN) : Index of an Extra Element
Day 146(9 JUN) : Convert array into Zig-Zag fashion
Day 147(10 JUN) : Nuts and Bolts Problem
Day 148(11 JUN) : Maximum Tip Calculator
Day 149(12 JUN) : Count numbers containing 4
Day 150(13 JUN) : Padovan Sequence
Day 151(14 JUN) : Armstrong Numbers
Day 152(15 JUN) : Mobile numeric keypad
Day 153(16 JUN) : Prime Pair with Target Sum
Day 154(18 JUN) : Number of Rectangles in a Circle
Day 155(19 JUN) : Find maximum volume of a cuboid
Day 156(20 JUN) : Integral Points Inside Triangle
Day 157(21 JUN) : Compare two fractions
Day 158(22 JUN) : Extract the Number from the String
Day 159(23 JUN) : Print Bracket Number
Day 160(24 JUN) : Summed Matrix
Day 161(25 JUN) : Left Rotate Matrix K times
Day 162(26 JUN) : Coverage of all Zeros in a Binary Matrix
Day 163(27 JUN) : Toeplitz matrix
Day 164(28 JUN) : The Palindrome Pattern
Day 165(1 JUL) : Make Binary Tree From Linked List
Day 166(2 JUL) : Linked list of strings forms a palindrome
Day 167(3 JUL) : Remove all occurences of duplicates in a linked list
Day 168(4 JUL) : Duplicate Subtrees
Day 169(5 JUL) : Vertical Width of a Binary Tree
Day 170(6 JUL) : Populate Inorder Successor for all nodes
Day 171(12 JUL) : Root to leaf path sum
Day 172(13 JUL) : Shortest Path in Weighted undirected graph
Day 173(14 JUL) : Segregate 0s and 1s
Day 174(15 JUL) : Smallest number
Day 175(16 JUL) : Remaining String
Day 176(17 JUL) : Construct Binary Tree from Parent Array
Day 177(18 JUL) : Longest alternating subsequence
Day 178(19 JUL) : Count Smaller elements
Day 179(20 JUL) : Remove Half Nodes
Day 180(21 JUL) : Maximum product subset of an array
Day 181(22 JUL) : Largest BST
Day 182(23 JUL) : Merge two BST 's
Day 183(24 JUL) : Check for BST
Day 184(25 JUL) : Array to BST
Day 185(26 JUL) : K-Pangrams
Day 186(27 JUL) : Form a palindrome
Day 187(28 JUL) : Remove Duplicates
Day 188(29 JUL) : Row with max 1s
Day 189(30 JUL) : Rat in a Maze Problem - I
Day 190(31 JUL) : Longest Common Prefix of Strings
Day 191(1 AUG) : Spirally traversing a matrix
Day 192(2 AUG) : Edit Distance
Day 193(3 AUG) : The Celebrity Problem
Day 194(4 AUG) : N meetings in one room
Day 195(5 AUG) : Bottom View of Binary Tree
Day 196(6 AUG) : Validate an IP Address
Day 197(7 AUG) : K-th element of two Arrays
Day 198(8 AUG) : Sum Tree
Day 199(9 AUG) : Maximize Array Value After Rearrangement
Day 200(10 AUG) : Rotate a Linked List
Day 201(11 AUG) : Job Sequencing Problem
Day 202(12 AUG) : Sum of Middle elements of two sorted arrays
Day 203(13 AUG) : Square root of a number
Day 204(14 AUG) : Longest Common Substring
Day 205(15 AUG) : Add 1 to a Linked List Number
Day 206(16 AUG) : Maximize The Cut Segments
Day 207(17 AUG) : Product array puzzle
Day 208(18 AUG) : Split an array into two equal Sum subarrays
Day 209(19 AUG) : Kth Smallest
Day 210(20 AUG) : Burning Tree
Day 211(21 AUG) : Shortest path in Undirected Graph
Day 212(22 AUG) : Alien Dictionary
Day 213(23 AUG) : Left View of Binary Tree
Day 214(24 AUG) : 0 - 1 Knapsack Problem
Day 215(25 AUG) : Number of pairs
Day 216(26 AUG) : Wildcard Pattern Matching
Day 217(27 AUG) : Maximum Difference
Day 218(28 AUG) : Sorting Elements of an Array by Frequency
Day 219(29 AUG) : Find length of Loop
Day 220(30 AUG) : N-Queen Problem
Day 221(31 AUG) : Sorted subsequence of size 3
Day 222(1 SEPT) : Max sum path in two arrays
Day 223(2 SEPT) : Minimum Cost Path
Day 224(3 SEPT) : Minimum number of deletions and insertions
Day 225(4 SEPT) : Count ways to N'th Stair(Order does not matter)
Day 226(5 SEPT) : Missing in Array
Day 227(6 SEPT) : Kadane's Algorithm
Day 228(7 SEPT) : Nth Natural Number
Day 229(8 SEPT) : Minimum Jumps
Day 230(9 SEPT) : Sort 0s, 1s and 2s
Day 231(10 SEPT) : Circle of strings
Day 232(11 SEPT) : Minimum Cost of ropes
Day 233(12 SEPT) : Middle of a Linked List
Day 234(13 SEPT) : Mirror Tree
Day 235(14 SEPT) : Alternate positive and negative numbers
Day 236(15 SEPT) : Binary Tree to DLL
Day 237(16 SEPT) : Longest valid Parentheses
Day 238(17 SEPT) : Minimize the Heights II
Day 239(18 SEPT) : Parenthesis Checker
Day 240(19 SEPT) : Reverse Words
Day 241(20 SEPT) : Facing the sun
Day 242(21 SEPT) : Clone a linked list with next and random pointer
Day 243(22 SEPT) : Longest Prefix Suffix
Day 244(23 SEPT) : Missing And Repeating
Day 245(24 SEPT) : Smallest window in a string containing all the characters of another string
Day 246(25 SEPT) : Palindrome Linked List
Day 247(26 SEPT) : Roof Top
Day 248(27 SEPT) : K Sized Subarray Maximum
Day 249(28 SEPT) : Minimal Cost
Day 250(29 SEPT) : Total count
Day 251(30 SEPT) : Merge two BST 's(New Approach)
Day 252(01 OCT) : Multiply two linked lists
Day 253(02 OCT) : Rotate and delete
Day 254(03 OCT) : Majority Vote
Day 255(04 OCT) : Deletion and Reverse in Circular Linked List
Day 256(05 OCT) : Not a subset sum
Day 257(06 OCT) : Find the number of islands
Day 258(07 OCT) : XOR Linked List
Day 259(08 OCT) : Largest Pair Sum
Day 260(09 OCT) : Linked List Matrix
Day 261(10 OCT) : Max distance between same elements
Day 262(11 OCT) : Reorganize The Array
Day 263(12 OCT) : Two Smallests in Every Subarray
Day 264(13 OCT) : Delete Alternate Nodes
Day 265(14 OCT) : Count Linked List Nodes
Day 266(15 OCT) : Subarray range with given sum
Day 267(16 OCT) : Two Swaps
Day 268(17 OCT) : Split Linked List Alternatingly
Day 269(18 OCT) : Single Number