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