1. Water Jug Problem using Memoization
  2. Count number of triplets with product equal to given number with duplicates allowed
  3. Number of ways to divide a given number as a set of integers in decreasing order
  4. Generating subarrays using recursion
  5. Generating all possible Subsequences using Recursion
  6. Why does sizeof(x++) not increment x in C?
  7. Address Calculation Sort using Hashing
  8. Check if the given 2-D points form T-shape or not
  9. Johnson’s algorithm for All-pairs shortest paths | Implementation
  10. 2-3 Trees | (Search and Insert)
  11. Is sizeof for a struct equal to the sum of sizeof of each member?
  12. Find if an undirected graph contains an independent set of a given size
  13. Minimum difference between the highest and the smallest value of mines distributed
  14. Printing all subsets of {1,2,3,...n} without using array or loop
  15. Clone a stack without extra space
  16. Nested List Comprehensions in Python
  17. Number of Walks from source to destination
  18. Comprehensions in Python
  19. Find maximum distance between any city and station
  20. Iterate over a dictionary in Python
  21. Python | Create a Pandas Dataframe from a dict of equal length lists
  22. Maximum even length sub-string that is permutation of a palindrome
  23. How to rename columns in Pandas DataFrame
  24. Python | Sort list of dates given as strings
  25. Longest Ordered Subsequence of Vowels
  26. Sub-strings of a string that are prefix of the same string
  27. Python program to print the substrings that are prefix of the given string
  28. CSS | transition-property Property
  29. CSS | Pseudo-classes
  30. Print first n distinct permutations of string using itertools in Python
  31. Python | Implementing 3D Vectors using dunder methods
You may use GeeksforGeeks CONTRIBUTE portal to help other geeks. For more info, please refer this.

  1. Union and Intersection of two sorted arrays
  2. Find the smallest window in a string containing all characters of another string
  3. Interleaving of two given strings with no common characters
  4. Given a sequence of words, print all anagrams together | Set 1
  5. Check whether a given graph is Bipartite or not
  6. Expression Evaluation
  7. Find the element before which all the elements are smaller than it, and after which all are greater
  8. Convert a Binary Tree to Threaded binary tree | Set 1 (Using Queue)
  9. Longest Even Length Substring such that Sum of First and Second Half is same
  10. Group multiple occurrence of array elements ordered by first occurrence
  11. Find sum of all elements in a matrix except the elements in row and/or column of given cell?
  12. Find all possible outcomes of a given expression
  13. Combinatorial Game Theory | Set 3 (Grundy Numbers/Nimbers and Mex)
  14. Number of Integral Points between Two Points
  15. Fifth root of a number
  16. Find subarray with given sum | Set 2 (Handles Negative Numbers)
  17. Maximum product of a triplet (subsequnece of size 3) in array
  18. Maximum profit by buying and selling a share at most k times
  19. Pair with given product | Set 1 (Find if any pair exists)
  20. Minimax Algorithm in Game Theory | Set 2 (Introduction to Evaluation Function)
  21. Rearrange a string so that all same characters become atleast d distance away
  22. Longest Common Prefix using Divide and Conquer Algorithm
  23. Rearrange positive and negative numbers with constant extra space
  24. Maximize arr[j] - arr[i] + arr[l] - arr[k], such that i < j < k < l
  25. Minimax Algorithm in Game Theory | Set 4 (Alpha-Beta Pruning)
  26. Find if an expression has duplicate parenthesis or not
  27. Minimum characters to be added at front to make string palindrome
  28. Sieve of Eratosthenes in 0(n) time complexity
  29. Find elements which are present in first array and not in second
  30. Check whether row or column swaps produce maximum size binary sub-matrix with all 1s
  31. Maximum area of triangle having different vertex colors
  32. Count trailing zero bits using lookup table
  33. Maximize sum of N X N upper left sub-matrix from given 2N X 2N matrix
  34. Sorting possible using size 3 subarray rotation
  35. Check if a doubly linked list of characters is palindrome or not
  36. Search in an array of strings where non-empty strings are sorted
  37. Character replacement after removing duplicates from a string
  38. Minimum swaps to reach permuted array with at most 2 positions left swaps allowed
  39. Count of arrays in which all adjacent elements are such that one of them divide the another
  40. Maximum sum two non-overlapping subarrays of given size
  41. TimSort
  42. Number of times the largest perfect square number can be subtracted from N
  43. Find Index of 0 to be replaced with 1 to get longest continuous sequence of 1s in a binary array | Set-2
  44. Check if a king can move a valid move or not when N nights are there in a modified chessboard
  45. Non-overlapping sum of two sets
  46. Shortest path between two nodes in array like representation of binary tree
  47. Minimum Fibonacci terms with sum equal to K
  48. Remove one bit from a binary number to get maximum value
  49. Count of Palindromic substrings in an Index range
  50. Find the Sub-array with sum closest to 0
  51. Print the string by ignoring alternate occurrences of any character
  52. Find numbers of balancing positions in string
  53. Maximum score after flipping a Binary Matrix atmost K times
  54. Reverse a Linked List according to its Size
  55. Maximum possible sum of a window in an array such that elements of same window in other array are unique
  56. Find n-th lexicographically permutation of a string | Set 2
  57. Calculate number of nodes in all subtrees | Using DFS
  58. A modified game of Nim
  59. Find the n-th number whose binary representation is a palindrome
  60. Minimum cells traversed to reach corner where every cell represents jumps
  61. Check if a grid can become row-wise and column-wise sorted after adjacent swaps
  62. Count pairs in an array such that LCM(arr[i], arr[j]) > min(arr[i],arr[j])
  63. Check if the string contains consecutive letters and each letter occurs exactly once
  64. Minimum operation to make all elements equal in array
  65. Check if there is a cycle with odd weight sum in an undirected graph
  66. Rearrangement of a number which is also divisible by it
  67. Check if given array is almost sorted (elements are at-most one position away)
  68. Maximum length subsequence with difference between adjacent elements as either 0 or 1 | Set 2
  69. Largest subarray having sum greater than k
  70. Longest Common Subsequence with at most k changes allowed
  71. Node having maximum sum of immediate children and itself in n-ary tree
  72. Replace two substrings (of a string) with each other
  73. Maximum length subsequence possible of the form R^N K^N
  74. Check if the given array can represent Level Order Traversal of Binary Search Tree
  75. Cumulative frequency of count of each element in an unsorted array
  76. Index Mapping (or Trivial Hashing) with negatives allowed
  77. Distinct permutations of the string | Set 2
  78. Smallest subarray with k distinct numbers
  79. Distributing items when a person cannot take more than two items of same type
  80. Products of ranges in an array
  81. Sorting using trivial hash function
  82. Differences between number of increasing subarrays and decreasing subarrays in k sized windows
  83. Next word that does not contain a palindrome and has characters from first k
  84. Number of GP (Geometric Progression) subsequences of size 3
  85. Sparse Table
  86. Minimum characters to be replaced to remove the given substring
  87. Minimum array element changes to make its elements 1 to N
  88. Select a Random Node from a tree with equal probability
  89. Queries for frequencies of characters in substrings
  90. Total numbers with no repeated digits in a range
  91. Remove all outgoing edges except edge with minimum weight
  92. Subtree of all nodes in a tree using DFS
  93. Area of hexagon with given diagonal length
  94. Find maximum number of elements such that their absolute difference is less than or equal to 1
  95. Sum of maximum elements of all possible sub-arrays of an array
  96. Why does sizeof(x++) not increment x in C?
  97. Sum of each element raised to (prime-1) % prime
  98. Invert actual bits of a number
  99. n-th number whose sum of digits is ten
  100. Schedule jobs so that each server gets equal load
  101. Maximum Product Subarray | Added negative product case
  102. Number of subarrays having sum exactly equal to k
  103. Hypercube Graph
  104. Number of subsets with product less than k
  105. Number of Unicolored Paths between two nodes
  106. Dynamic Disjoint Set Data Structure for large range values
  107. Fibonacci Cube Graph
  108. Euler's Four Square Identity
  109. Sum of nodes at maximum depth of a Binary Tree
  110. Leftover element after performing alternate Bitwise OR and Bitwise XOR operations on adjacent pairs
  111. First element that appears even number of times in an array
  112. Largest palindromic number by permuting digits
  113. Check if number can be displayed using seven segment led
  114. Check if it possible to partition in k subarrays with equal sum
  115. Longest Palindromic Substring using Palindromic Tree | Set 3
  116. Minimum cost to process m tasks where switching costs
  117. Number of single cycle components in an undirected graph
  118. Maximum adjacent difference in an array in its sorted form
  119. Find if k bookings possible with given arrival and departure times
  120. Lexicographically Kth smallest way to reach given coordinate from origin
  121. Check if it is possible to make the given matrix increasing matrix or not
  122. Print Longest substring without repeating characters
  123. Students with maximum average score of three subjects
  124. Given two numbers as strings, find if one is a power of other
  125. Sort the biotonic doubly linked list | Set-2
  126. Check if given Sudoku board configuration is valid or not
  127. Check if a string can be formed from another string using given constraints
  128. Check if two trees are mirror of each other using level order traversal
  129. Check if two nodes are cousins in a Binary Tree | Set-2
  130. Number of Unique BST with a given key | Dynamic Programming
  131. Count the number of intervals in which a given value lies
  132. Print all distinct integers that can be formed by K numbers from a given array of N numbers
  133. Rearrange a Linked List in Zig-Zag fashion | Set-2
  134. Make all numbers of an array equal
  135. Level order traversal with direction change after every two levels | Recursive Approach
  136. Program to print last N lines | Set-2
  137. Element which occurs consecutively in a given subarray more than or equal to K times
  138. Maximize the sum of X+Y elements by picking X and Y elements from 1st and 2nd array
  139. Print levels with odd number of nodes and even number of nodes
  140. Minimum changes needed to make a 3*3 matrix magic square
  141. Maximum bishops that can be placed on N*N chessboard
  142. Smallest divisor D of N such that gcd(D, M) is greater than 1
  143. Print all the pairs that contains the positive and negative values of an element
  144. Maximum power of jump required to reach the end of string
  145. Number of ways to represent a number as sum of k fibonacci numbers
  146. Shortest distance between two nodes in an infinite binary tree
  147. Check if is possible to get given sum from a given set of elements
  148. Longest subsequence whose average is less than K
  149. Maximum value of XOR among all triplets of an array
  150. Longest common anagram subsequence from N strings
  151. Add two unsigned numbers using bits
  152. Sum of all elements repeating 'k' times in an array
  153. Split array to three subarrays such that sum of first and third subarray is equal and maximum
  154. Tail recursion to calculate sum of array elements.
  155. Number of divisors of product of N numbers
  156. Minimize ASCII values sum after removing all occurrences of one character
  157. Product of lengths of all cycles in an undirected graph
  158. Lexicographically smallest permutation of a string with given subsequences
  159. Minimum operation require to make first and last character same
  160. Generating subarrays using recursion
  161. Longest subarray having difference in the count of 1's and 0's equal to k
  162. Minimum number of palindromes required to express N as a sum | Set 2
  163. Count numbers (smaller than or equal to N) with given digit sum
  164. Program to find the diameter, cycles and edges of a Wheel Graph
  165. Count number of integers less than or equal to N which has exactly 9 divisors
  166. Sum of minimum elements of all subarrays
  167. Length of largest sub-array having primes strictly greater than non-primes
  168. Replace even nodes of a doubly linked list with the elements of array
  169. Number of values of b such that a = b + (a^b)
  170. Replace minimal number of characters to make all characters pair wise distinct
  171. Rearrange the string to maximize the number of palindromic substrings
  172. Queries to add, remove and return the difference of maximum and minimum.
  173. Check if an integer can be expressed as a sum of two semi-primes
  174. Hammered distance between N points in a 2-D plane
  175. Maximum removal from array when removal time >= waiting time
  176. Check whether the given number is Euclid Number or not
  177. Count the number of pop operations on stack to get each element of the array
  178. Maximize the number of subarrays with XOR as zero
  179. Ulam Number Sequence
  180. Sum of every K'th prime number in an array
  181. Minimum Bitwise AND operations to make any two array elements equal
  182. Check if all sub-numbers have distinct Digit product
  183. Gould's Sequence
  184. Check if suffix and prefix of a string are palindromes
  185. Find the winner of the game with N piles of boxes
  186. Check if the given number is Ore number or not
  187. Check whether a binary string can be formed by concatenating given N numbers sequentially
  188. Maximum number of fixed points using atmost 1 swap
  189. Largest element in the array that is repeated exactly k times
  190. Check if a pair with given product exists in Linked list
  191. Numbers that are bitwise AND of at least one non-empty sub-array
  192. Sub-strings having exactly k characters that have ASCII value greater than p
  193. Check if the frequency of all the digits in a number is same
  194. Sort prime numbers of an array in descending order
  195. Number of anomalies in an array
  196. All possible numbers of N digits and base B without leading zeros
  197. Minimum number of bottles required to fill K glasses
  198. Find two non-overlapping pairs having equal sum in an Array
  199. Online Queries for GCD of array after divide operations
  200. Triplet pair (a, b, c) such that a+b, b+c and a+c are all divisible by K
  201. Find minimum speed to finish all Jobs
  202. Permutation of an array that has smaller values from another array
  203. Python | range() does not return an iterator
  204. Find length of longest Fibonacci like subsequence
  205. Check if it is possible to rearrange a binary string with alternate 0s and 1s
  206. Check if there is any pair in a given range with GCD is divisible by k
  207. Get K-th letter of the decoded string formed by repeating substrings
  208. String after processing backspace characters
  209. Shift all prefixes by given lengths
  210. Maximizing the elements with a[i+1] > a[i]
  211. Count Magic squares in a grid
  212. Rearrange an array to maximize i*arr[i]
  213. String matching with * (that matches with any) in any of the two strings
  214. Minimize Cost with Replacement with other allowed
  215. String with frequency of characters in Lucas Sequence
  216. Convert all lowercase characters to uppercase whose ASCII value is co-prime with k
  217. Replace all consonants with nearest vowels in a string
  218. XOR of all Prime numbers in an Array
  219. Number of ways to partition a string into two balanced subsequences
  220. Minimum array elements to be changed to make it a Lucas Sequence
  221. Most frequent word in first String which is not present in second String
  222. Count of Prime Nodes of a Singly Linked List
  223. Check whether frequency of characters in a string makes Fibonacci Sequence
  224. Shortest distance to every other character from given character
  225. XOR of Prime Frequencies of Characters in a String
  226. Count pairs in an array such that frequency of one is at least value of other
  227. Count occurrences of the average of array elements with a given number
  228. Number of sub-arrays that have at least one duplicate
  229. Minimum number of elements to be replaced to make the given array a Fibonacci Sequence
  230. Check if frequency of character in one string is a factor or multiple of frequency of same character in other string
  231. Count subarrays with Prime sum
  232. Find all good indices in the given Array
  233. Ways to form n/2 pairs such that difference of pairs is minimum
  234. Different possible marks for n questions and negative marking
  235. Smallest prime number missing in an array
  236. Minimum and maximum node that lies in the path connecting two nodes in a Binary Tree
  237. Find the missing elements from 1 to M in given N ranges
  238. Print all pairs in an unsorted array with equal sum
  239. Count distinct pairs from two arrays having same sum of digits
  240. Find a value whose XOR with given number is maximum
  241. Number of blocks in a chessboard a knight can move to in exactly k moves
  242. Check if the given push and pop sequences of Stack is valid or not
  243. Count pairs (A, B) such that A has X and B has Y number of set bits and A+B = C
  244. Maximum sum subarray such that start and end values are same
  245. Closest greater or same value on left side for every element in array
  246. Find if there is any subset of size K with 0 sum in an array of -1 and +1
  247. Check if N can be represented as sum of integers chosen from set {A, B}
  248. Lexicographically Smallest Permutation of length N such that for exactly K indices, a[i] > a[i] + 1
  249. Count number of indices such that s[i] = s[i+1] : Range queries
  250. Maximize the median of an array
  251. Find a range that covers all the elements of given N ranges
  252. Fill missing entries of a magic square
  253. Level Order Successor of a node in Binary Tree
  254. Check if array can be sorted with one swap
  255. Print numbers with digits 0 and 1 only such that their sum is N
  256. Number of comparisons in each direction for m queries in linear search
  257. Replace the middle element of matrix with sum of surrounding elements
  258. Number of triangles that can be formed with given N points
  259. Level with maximum number of nodes using DFS in a N-ary tree
  260. Digits of element wise sum of two arrays into a new array
  261. Construct a binary string following the given constraints
  262. Move all special char to the end of the String
  263. Find the only different element in an array
  264. Puzzle | 1000 light bulbs switched on/off by 1000 persons passing by
  265. Minimum moves required to change position with the given operation
  266. Check if elements of an array can be arranged satisfying the given condition
  267. Find the minimum positive integer such that it is divisible by A and sum of its digits is equal to B
  268. Sum of first N natural numbers when N is extremely large
  269. Maximum possible time that can be formed from four digits
  270. Largest Divisor of a Number not divisible by a perfect square
  271. Find k-th character of decrypted string | Set - 2
  272. Summing the sum series
  273. Most frequent factor in a range of integers
  274. Program to print the given H Pattern
  275. Update adjacent nodes if the current node is zero in a Singly Linked List
  276. Find numbers a and b that satisfy the given conditions
  277. Count numbers < = N whose difference with the count of primes upto them is > = K
  278. Substring Reverse Pattern
  279. Sum of element whose prime factors are present in array
  280. Minimum K such that every substring of length atleast K contains a character c
  281. Minimum Operations to make value of all vertices of the tree Zero
  282. Sum of LCM(1, n), LCM(2, n), LCM(3, n), ... , LCM(n, n)
  283. Count of Numbers in a Range divisible by m and having digit d in even positions
  284. Check if a number is perfect square without finding square root
  285. Choose n elements such that their mean is maximum
  286. Pairs with same Manhattan and Euclidean distance
  287. Assign weights to edges such that longest path in terms of weights is minimized
  288. Check whether a + b = c or not after removing all zeroes from a,b and c
  289. Represent n as the sum of exactly k powers of two | Set 2
  290. Finding in and out degrees of all vertices in a graph
  291. Count rows in a matrix that consist of same element
  292. Print all integers that are sum of powers of two given numbers
  293. Possible cuts of a number such that maximum parts are divisible by 3
  294. Weighted sum of the characters of a string in an array | Set 2
  295. Cost to make a string Panagram | Set 2
  296. Check if it is possible to get back to 12'0 clock only by adding or subtracting given seconds
  297. Check if a string can be repeated to make another string
  298. Largest number less than or equal to N/2 which is coprime to N
  299. Reverse Middle X Characters
  300. Check if the binary representation of a number has equal number of 0s and 1s in blocks
  301. Replace each node with its Surpasser Count in Linked List
  302. Finding the path from one vertex to rest using BFS
  303. Count strings that end with the given pattern
  304. Find safe cells in a matrix
  305. Find the resulting Colour Combination
  306. Water Game
  307. Remove first X rows and columns from a matrix
  308. Divide N segments into two non-empty groups such that given condition is satisfied
  309. Minimum operations of given type to make all elements of a matrix equal
  310. Maximum given sized rectangles that can be cut out of a sheet of paper
  311. Generate a random permutation of 1 to N
  312. Count all Prime Length Palindromic Substrings
  313. Increasing sequence with given GCD
  314. Check if a binary string contains consecutive same or not
  315. Cost of painting n * m grid
  316. Count Odd and Even numbers in a range from L to R
  317. Find the lexicographically largest palindromic Subsequence of a String
  318. Make palindromic string non-palindromic by rearranging its letters
  319. Minimum number of edges between two vertices of a graph using DFS
  320. Sub-string that contains all lowercase alphabets after performing the given operation
  321. Minimum operations required to modify the array such that parity of adjacent elements is different
  322. Find the cordinates of the fourth vertex of a rectangle with given 3 vertices
  323. Minimum number of operations on an array to make all elements 0
  324. Sum of minimum elements of all possible sub-arrays of an array
  325. Maximum number of segments that can contain the given points
  326. Program to reverse a linked list using Stack
  327. Count possible moves in the given direction in a grid
  328. Shortest path to traverse all the elements of a circular array in increasing order
  329. Reverse zigzag Traversal of a Binary Tree
  330. Count of words that are present in all the given sentences
  331. Sum of XOR of all subarrays
  332. Delete nodes which have a greater value on right side using recursion
  333. DP on Trees | Set-3 ( Diameter of N-ary Tree )
  334. Print the first shortest root to leaf path in a Binary Tree
  335. Search element in a Spirally sorted Matrix
  336. Merge K sorted arrays of different sizes | ( Divide and Conquer Approach )
  337. Minimum edges to be added in a directed graph so that any node can be reachable from a given node
  338. Count of numbers between range having only non-zero digits whose sum of digits is N and number is divisible by M
  339. Zig-Zag traversal of a Binary Tree using Recursion
  340. Minimum operations to make counts of remainders same in an array
  341. Print All Leaf Nodes of a Binary Tree from left to right | Set-2 ( Iterative Approach )
  342. Find the Nth term of the series where each term f[i] = f[i - 1] - f[i - 2]
  343. Number of submatrices with OR value 1
  344. Minimum possible sum of array elements after performing the given operation
  345. Number of submatrices with all 1s
  346. Bitwise AND of N binary strings
  347. Number of unique paths in tree such that every path has a value greater than K
  348. Print the lexicographically smallest DFS of the graph starting from 1
  349. Maximum length of the sub-array whose first and last elements are same
  350. Longest Sub-array with maximum average value
  351. Sum of bitwise AND of all submatrices
  352. Sum of Bitwise-OR of all Submatrices
  353. Double Knapsack | Dynamic Programming
  354. Minimum operations to make frequency of all characters equal K
  355. Count pairs (p, q) such that p occurs in array at least q times and q occurs at least p times
  356. Number of special nodes in an n-ary tree
  357. Check if frequency of characters are in Recaman Series
  358. Character pairs from two strings with even sum
  359. Number of ways to select a node from each connected component
  360. Time until distance gets equal to X between two objects moving in opposite direction
  361. Sum of numbers from 1 to N which are in Fibonacci Sequence
  362. Minimum number of replacements to make the binary string alternating | Set 2
  363. Longest double string from a Palindrome
  364. Minimum number of bracket reversals needed to make an expression balanced | Set - 2
  365. Sum of the series (1*2) + (2*3) + (3*4) + ...... upto n terms
  366. Largest subset of rectangles such that no rectangle fit in any other rectangle
  367. Sum of nodes in top view of binary tree
  368. Find the K-th minimum element from an array concatenated M times
  369. Sum of all even factors of numbers in the range [l, r]
  370. Longest path in a directed Acyclic graph | Dynamic Programming
  371. Print the balanced bracket expression using given brackets
  372. Encrypt a string by repeating i-th character i times
  373. Count of all N digit numbers such that num + Rev(num) = 10^N - 1
  374. Sum of (maximum element - minimum element) for all the subsets of an array.
  375. Find A and B from list of divisors
  376. Character whose frequency is equal to the sum of frequencies of other characters of the given string
  377. Distinct state codes that appear in a string as contiguous sub-strings
  378. Sum of nodes in bottom view of Binary Tree
  379. Check if the given string is K-periodic
  380. Check if a Queen can attack a given cell on chessboard
  381. Smallest and Largest N-digit perfect cubes
  382. Addition of two numbers without propagating Carry
  383. Number of steps required to reach point (x,y) from (0,0) using zig-zag way
  384. Minimum cuts required to convert a palindromic string to a different palindromic string
  385. Find maximum N such that the sum of square of first N natural numbers is not more than X
  386. Generate all the binary strings of N bits
  387. Position of the K-th set bit in a number
  388. Find the number of good permutations
  389. Minimum length of square to contain at least half of the given Coordinates
  390. Maximum count of pairs which generate the same sum
  391. Count integers in a range which are divisible by their euler totient value
  392. Find foot of perpendicular from a point in 2 D plane to a Line
  393. Find a pair from the given array with maximum nCr value
  394. Minimum steps to delete a string by deleting substring comprising of same characters
  395. Maximum sum from three arrays such that picking elements consecutively from same is not allowed
  396. Count of buttons pressed in a keypad mobile
  397. Correct the Random Pointer in Doubly Linked List
  398. Minimum cost to reach end of array array when a maximum jump of K index is allowed
  399. Check if the given binary tree has a sub-tree with equal no of 1's and 0's | Set 2
  400. Program to calculate Double Integration
  401. Maximize the value of the given expression
  402. Loss when two items are sold at same price and same percentage profit/loss
  403. Total distinct pairs of ugly numbers from two arrays
  404. Sort ugly numbers in an array at their relative positions
  405. Times required by Simple interest for the Principal to become Y times itself
  406. Iterative approach to check for children sum property in a Binary Tree
  407. Generate all binary strings of length n with sub-string "01" appearing exactly twice
  408. Length of the longest substring that do not contain any palindrome
  409. Arrange given numbers to form the smallest number
  410. Maximum Subarray Sum after inverting at most two elements
  411. Find number of edges that can be broken in a tree such that Bitwise OR of resulting two trees are equal
  412. Find the longest subsequence of an array having LCM at most K
  413. Sum of two numbers where one number is represented as array of digits
  414. Number of ways for playing first move optimally in a NIM game
  415. Number of ways of choosing K equal substrings of any length for every query
  416. Area of the biggest ellipse inscribed within a rectangle
  417. Minimum number of given operations required to convert a permutation into an identity permutation
  418. Find the count of sub-strings whose characters can be rearranged to form the given word
  419. Count all prefixes of the given binary array which are divisible by x
  420. Count consecutive pairs of same elements
  421. Iterative selection sort for linked list
  422. Print path from root to all nodes in a Complete Binary Tree
  423. Convert the undirected graph into directed graph such that there is no path of length greater than 1
  424. Find triplet such that number of nodes connecting these triplets is maximum
  425. Length of the longest substring with no consecutive same letters
  426. Find number of unique triangles among given N triangles
  427. Sum of all distinct nodes in a linked list
  428. Sum of smaller elements of nodes in a linked list
  429. Divide a number into two parts
  430. Check if the given Binary Expressions are valid
  431. Number of Positions to partition the string such that atleast m characters with same frequency are present in each substring
  432. Find the kth node in vertical order traversal of a Binary Tree
  433. Maximum length cycle that can be formed by joining two nodes of a binary tree
  434. Game Theory in Balanced Ternary Numeral System | (Moving 3k steps at a time)
  435. Kth largest node among all directly connected nodes to the given node in an undirected graph
  436. Maximum sum of non-leaf nodes among all levels of the given binary tree
  437. Sum of all parent-child differences in a Binary Tree
  438. Arrange array elements such that last digit of an element is equal to first digit of the next element
  439. Find an index such that difference between product of elements before and after it is minimum
  440. Maximum Sum SubArray using Divide and Conquer | Set 2
  441. Find sub-arrays from given two arrays such that they have equal sum
  442. Count number of subsets whose median is also present in the same subset
  443. Smallest multiple of N formed using the given set of digits
  444. Minimum number of given operations required to reduce the array to 0 element
  445. K-th ancestor of a node in Binary Tree | Set 3
  446. Sum of the mirror image nodes of a complete binary tree in an inorder way
  447. Count the number of primes in the prefix sum array of the given array
  448. Maximum possible middle element of the array after deleting exactly k elements
  449. Print the degree of every node from the given Prufer sequence