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Trees

HackWithInfy Prep • 264 items

1Add One Row to TreeMedium
TreeDepth-First SearchBreadth-First Search
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2All Elements in Two Binary Search TreesMedium
TreeDepth-First SearchBinary Search Tree
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3All Nodes Distance K in Binary TreeMedium
Hash TableTreeDepth-First Search
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4Amount of New Area Painted Each DayHard
ArraySegment TreeOrdered Set
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5Amount of Time for Binary Tree to Be InfectedMedium
Hash TableTreeDepth-First Search
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6Average of Levels in Binary TreeEasy
TreeDepth-First SearchBreadth-First Search
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7Balance a Binary Search TreeMedium
Divide and ConquerGreedyTree
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8Balanced Binary TreeEasy
TreeDepth-First SearchBinary Tree
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9Binary Search Tree Iterator IIMedium
StackTreeDesign
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10Binary Search Tree IteratorMedium
StackTreeDesign
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11Binary Search Tree to Greater Sum TreeMedium
TreeDepth-First SearchBinary Search Tree
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12Binary Tree Coloring GameMedium
TreeDepth-First SearchBinary Tree
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13Binary Tree Inorder TraversalEasy
StackTreeDepth-First Search
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14Binary Tree Level Order Traversal IIMedium
TreeBreadth-First SearchBinary Tree
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15Binary Tree Level Order TraversalMedium
TreeBreadth-First SearchBinary Tree
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16Binary Tree Longest Consecutive Sequence IIMedium
TreeDepth-First SearchBinary Tree
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17Binary Tree Longest Consecutive SequenceMedium
TreeDepth-First SearchBinary Tree
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18Binary Tree PathsEasy
StringBacktrackingTree
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19Binary Tree Postorder TraversalEasy
StackTreeDepth-First Search
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20Binary Tree Preorder TraversalEasy
StackTreeDepth-First Search
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21Binary Tree PruningMedium
TreeDepth-First SearchBinary Tree
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22Binary Tree Right Side ViewMedium
TreeDepth-First SearchBreadth-First Search
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23Binary Tree TiltEasy
TreeDepth-First SearchBinary Tree
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24Binary Tree Upside DownMedium
TreeDepth-First SearchBinary Tree
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25Binary Tree Vertical Order TraversalMedium
Hash TableTreeDepth-First Search
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26Binary Tree Zigzag Level Order TraversalMedium
TreeBreadth-First SearchBinary Tree
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27Block Placement QueriesHard
ArrayBinary SearchBinary Indexed Tree
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28Booking Concert Tickets in GroupsHard
Binary SearchDesignBinary Indexed Tree
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29Boundary of Binary TreeMedium
TreeDepth-First SearchBinary Tree
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30Build Binary Expression Tree From Infix ExpressionHard
StringStackTree
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31Change the Root of a Binary TreeMedium
TreeDepth-First SearchBinary Tree
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32Check Completeness of a Binary TreeMedium
TreeBreadth-First SearchBinary Tree
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33Check if DFS Strings Are PalindromesHard
ArrayHash TableString
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34Check If Two Expression Trees are EquivalentMedium
Hash TableTreeDepth-First Search
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35Checking Existence of Edge Length Limited Paths IIHard
Depth-First SearchUnion-FindGraph Theory
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36Clone Binary Tree With Random PointerMedium
Hash TableTreeDepth-First Search
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37Clone N-ary TreeMedium
Hash TableTreeDepth-First Search
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38Closest Binary Search Tree Value IIHard
Two PointersStackTree
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39Closest Binary Search Tree ValueEasy
Binary SearchTreeDepth-First Search
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40Closest Leaf in a Binary TreeMedium
TreeDepth-First SearchBreadth-First Search
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41Closest Node to Path in TreeHard
ArrayTreeDepth-First Search
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42Closest Nodes Queries in a Binary Search TreeMedium
ArrayBinary SearchTree
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43Collect Coins in a TreeHard
ArrayTreeGraph Theory
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44Complete Binary Tree InserterMedium
TreeBreadth-First SearchDesign
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45Connecting Cities With Minimum CostMedium
Union-FindGraph TheoryHeap (Priority Queue)
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46Construct Binary Search Tree from Preorder TraversalMedium
ArrayStackTree
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47Construct Binary Tree from Inorder and Postorder TraversalMedium
ArrayHash TableDivide and Conquer
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48Construct Binary Tree from Preorder and Inorder TraversalMedium
ArrayHash TableDivide and Conquer
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49Construct Binary Tree from Preorder and Postorder TraversalMedium
ArrayHash TableDivide and Conquer
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50Construct Binary Tree from StringMedium
StringStackTree
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51Construct Quad TreeMedium
ArrayDivide and ConquerTree
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52Construct String from Binary TreeMedium
StringTreeDepth-First Search
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53Convert Binary Search Tree to Sorted Doubly Linked ListMedium
Linked ListStackTree
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54Convert BST to Greater TreeMedium
TreeDepth-First SearchBinary Search Tree
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55Convert Sorted Array to Binary Search TreeEasy
ArrayDivide and ConquerTree
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56Convert Sorted List to Binary Search TreeMedium
Linked ListDivide and ConquerTree
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57Correct a Binary TreeMedium
Hash TableTreeDepth-First Search
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58Count Complete Tree NodesEasy
Binary SearchBit ManipulationTree
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59Count Good Nodes in Binary TreeMedium
TreeDepth-First SearchBreadth-First Search
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60Count Good Triplets in an ArrayHard
ArrayBinary SearchDivide and Conquer
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61Count Integers in IntervalsHard
DesignSegment TreeOrdered Set
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62Count Nodes Equal to Average of SubtreeMedium
TreeDepth-First SearchBinary Tree
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63Count Nodes Equal to Sum of DescendantsMedium
TreeDepth-First SearchBinary Tree
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64Count Nodes With the Highest ScoreMedium
ArrayTreeDepth-First Search
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65Count Non-Decreasing Subarrays After K OperationsHard
ArrayStackSegment Tree
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66Count Number of Rectangles Containing Each PointMedium
ArrayHash TableBinary Search
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67Count of Range SumHard
ArrayBinary SearchDivide and Conquer
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68Count of Smaller Numbers After SelfHard
ArrayBinary SearchDivide and Conquer
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69Count Pairs of Connectable Servers in a Weighted Tree NetworkMedium
ArrayTreeDepth-First Search
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70Count Subarrays With More Ones Than ZerosMedium
ArrayHash TableBinary Search
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71Count the Number of K-Big IndicesHard
ArrayBinary SearchDivide and Conquer
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72Count Univalue SubtreesMedium
TreeDepth-First SearchBinary Tree
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73Cousins in Binary Tree IIMedium
Hash TableTreeDepth-First Search
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74Cousins in Binary TreeEasy
TreeDepth-First SearchBreadth-First Search
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75Create Binary Tree From DescriptionsMedium
ArrayHash TableTree
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76Create Components With Same ValueHard
ArrayMathTree
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77Create Sorted Array through InstructionsHard
ArrayBinary SearchDivide and Conquer
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78Cycle Length Queries in a TreeHard
ArrayTreeBinary Tree
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79Deepest Leaves SumMedium
TreeDepth-First SearchBreadth-First Search
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80Delete Leaves With a Given ValueMedium
TreeDepth-First SearchBinary Tree
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81Delete Node in a BSTMedium
TreeBinary Search TreeBinary Tree
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82Delete Nodes And Return ForestMedium
ArrayHash TableTree
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83Delete Tree NodesMedium
ArrayTreeDepth-First Search
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84Design an Expression Tree With Evaluate FunctionMedium
ArrayMathStack
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85Diameter of Binary TreeEasy
TreeDepth-First SearchBinary Tree
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86Diameter of N-Ary TreeMedium
TreeDepth-First Search
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87Distribute Coins in Binary TreeMedium
TreeDepth-First SearchBinary Tree
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88Distribute Elements Into Two Arrays IIHard
ArrayBinary Indexed TreeSegment Tree
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89Employee ImportanceMedium
ArrayHash TableTree
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90Equal Tree PartitionMedium
TreeDepth-First SearchBinary Tree
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91Evaluate Boolean Binary TreeEasy
TreeDepth-First SearchBinary Tree
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92Even Odd TreeMedium
TreeBreadth-First SearchBinary Tree
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93Extract Kth Character From The Rope TreeEasy
TreeDepth-First SearchBinary Tree
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94Falling SquaresHard
ArraySegment TreeOrdered Set
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95Fancy SequenceHard
MathDesignSegment Tree
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96Find a Corresponding Node of a Binary Tree in a Clone of That TreeEasy
TreeDepth-First SearchBreadth-First Search
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97Find a Value of a Mysterious Function Closest to TargetHard
ArrayBinary SearchBit Manipulation
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98Find All The Lonely NodesEasy
TreeDepth-First SearchBreadth-First Search
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99Find Bottom Left Tree ValueMedium
TreeDepth-First SearchBreadth-First Search
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100Find Building Where Alice and Bob Can MeetHard
ArrayBinary SearchStack
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101Find Critical and Pseudo-Critical Edges in Minimum Spanning TreeHard
Union-FindGraph TheorySorting
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102Find Diameter Endpoints of a TreeMedium
TreeBreadth-First SearchGraph Theory
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103Find Distance in a Binary TreeMedium
Hash TableTreeDepth-First Search
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104Find Duplicate SubtreesMedium
Hash TableTreeDepth-First Search
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105Find Elements in a Contaminated Binary TreeMedium
Hash TableTreeDepth-First Search
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106Find Largest Value in Each Tree RowMedium
TreeDepth-First SearchBreadth-First Search
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107Find Leaves of Binary TreeMedium
TreeDepth-First SearchBinary Tree
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108Find Minimum Diameter After Merging Two TreesHard
TreeDepth-First SearchBreadth-First Search
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109Find Mode in Binary Search TreeEasy
TreeDepth-First SearchBinary Search Tree
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110Find Nearest Right Node in Binary TreeMedium
TreeBreadth-First SearchBinary Tree
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111Find Root of N-Ary TreeMedium
Hash TableBit ManipulationTree
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112Find Subarray With Bitwise OR Closest to KHard
ArrayBinary SearchBit Manipulation
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113Find the Last Marked Nodes in TreeHard
TreeDepth-First Search
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114Find the Level of Tree with Minimum SumMedium
TreeDepth-First SearchBreadth-First Search
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115Find the Longest Valid Obstacle Course at Each PositionHard
ArrayBinary SearchBinary Indexed Tree
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116Find X Value of Array IIHard
ArrayMathSegment Tree
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117Flatten Binary Tree to Linked ListMedium
Linked ListStackTree
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118Flatten Nested List IteratorMedium
StackTreeDepth-First Search
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119Flip Equivalent Binary TreesMedium
TreeDepth-First SearchBinary Tree
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120Frog Position After T SecondsHard
TreeDepth-First SearchBreadth-First Search
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121Fruits Into Baskets IIEasy
ArrayBinary SearchSegment Tree
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122Fruits Into Baskets IIIMedium
ArrayBinary SearchSegment Tree
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123Handling Sum Queries After UpdateHard
ArraySegment Tree
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124Height of Binary Tree After Subtree Removal QueriesHard
ArrayTreeDepth-First Search
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125Increasing Order Search TreeEasy
StackTreeDepth-First Search
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126Inorder Successor in BST IIMedium
TreeBinary Search TreeBinary Tree
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127Inorder Successor in BSTMedium
TreeDepth-First SearchBinary Search Tree
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128Insert into a Binary Search TreeMedium
TreeBinary Search TreeBinary Tree
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129Insufficient Nodes in Root to Leaf PathsMedium
TreeDepth-First SearchBinary Tree
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130Invert Binary TreeEasy
TreeDepth-First SearchBreadth-First Search
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131K Empty SlotsHard
ArrayBinary Indexed TreeSegment Tree
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132K-th Largest Perfect Subtree Size in Binary TreeMedium
TreeDepth-First SearchSorting
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133Kill ProcessMedium
ArrayHash TableTree
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134Kth Largest Element in a StreamEasy
TreeDesignBinary Search Tree
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135Kth Largest Sum in a Binary TreeMedium
TreeBreadth-First SearchSorting
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136Kth Smallest Element in a BSTMedium
TreeDepth-First SearchBinary Search Tree
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137Leaf-Similar TreesEasy
TreeDepth-First SearchBinary Tree
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138Linked List in Binary TreeMedium
Linked ListTreeDepth-First Search
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139Longest Balanced Subarray IMedium
ArrayHash TableDivide and Conquer
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140Longest Balanced Subarray IIHard
ArrayHash TableDivide and Conquer
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141Longest Path With Different Adjacent CharactersHard
ArrayStringTree
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142Longest Special Path IIHard
ArrayHash TableTree
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143Longest Substring of One Repeating CharacterHard
ArrayStringSegment Tree
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144Longest Univalue PathMedium
TreeDepth-First SearchBinary Tree
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145Longest Uploaded PrefixMedium
Hash TableBinary SearchUnion-Find
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146Lowest Common Ancestor of a Binary Search TreeMedium
TreeDepth-First SearchBinary Search Tree
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147Lowest Common Ancestor of a Binary Tree IIMedium
TreeDepth-First SearchBinary Tree
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148Lowest Common Ancestor of a Binary Tree IIIMedium
Hash TableTwo PointersTree
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149Lowest Common Ancestor of a Binary Tree IVMedium
Hash TableTreeDepth-First Search
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150Lowest Common Ancestor of a Binary TreeMedium
TreeDepth-First SearchBinary Tree
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151Lowest Common Ancestor of Deepest LeavesMedium
Hash TableTreeDepth-First Search
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152Make Array EmptyHard
ArrayBinary SearchGreedy
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153Maximize Subarrays After Removing One Conflicting PairHard
ArraySegment TreeEnumeration
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154Maximize the Number of Target Nodes After Connecting Trees IMedium
TreeDepth-First SearchBreadth-First Search
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155Maximize the Number of Target Nodes After Connecting Trees IIHard
TreeDepth-First SearchBreadth-First Search
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156Maximum Area Rectangle With Point Constraints IMedium
ArrayMathBinary Indexed Tree
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157Maximum Area Rectangle With Point Constraints IIHard
ArrayMathBinary Indexed Tree
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158Maximum Average SubtreeMedium
TreeDepth-First SearchBinary Tree
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159Maximum Binary Tree IIMedium
TreeBinary Tree
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160Maximum Binary TreeMedium
ArrayDivide and ConquerStack
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161Maximum Depth of Binary TreeEasy
TreeDepth-First SearchBreadth-First Search
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162Maximum Depth of N-ary TreeEasy
TreeDepth-First SearchBreadth-First Search
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163Maximum Difference Between Node and AncestorMedium
TreeDepth-First SearchBinary Tree
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164Maximum Level Sum of a Binary TreeMedium
TreeDepth-First SearchBreadth-First Search
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165Maximum Number of Intersections on the ChartHard
ArrayHash TableMath
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166Maximum Number of K-Divisible ComponentsHard
TreeDepth-First Search
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167Maximum Product of Splitted Binary TreeMedium
TreeDepth-First SearchBinary Tree
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168Maximum Profitable Triplets With Increasing Prices IMedium
ArrayBinary Indexed TreeSegment Tree
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169Maximum Profitable Triplets With Increasing Prices IIHard
ArrayBinary Indexed TreeSegment Tree
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170Maximum Width of Binary TreeMedium
TreeDepth-First SearchBreadth-First Search
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171Maximum XOR of Two Non-Overlapping SubtreesHard
TreeDepth-First SearchGraph Theory
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172Merge BSTs to Create Single BSTHard
ArrayHash TableTree
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173Merge Two Binary TreesEasy
TreeDepth-First SearchBreadth-First Search
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174Min Cost to Connect All PointsMedium
ArrayUnion-FindGraph Theory
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175Minimum Absolute Difference in BSTEasy
TreeDepth-First SearchBreadth-First Search
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176Minimum Depth of Binary TreeEasy
TreeDepth-First SearchBreadth-First Search
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177Minimum Distance Between BST NodesEasy
TreeDepth-First SearchBreadth-First Search
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178Minimum Edge Weight Equilibrium Queries in a TreeHard
ArrayTreeGraph Theory
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179Minimum Fuel Cost to Report to the CapitalMedium
TreeDepth-First SearchBreadth-First Search
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180Minimum Number of Moves to Make PalindromeHard
Two PointersStringGreedy
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181Minimum Number of Operations to Sort a Binary Tree by LevelMedium
TreeBreadth-First SearchBinary Tree
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182Minimum Score After Removals on a TreeHard
ArrayBit ManipulationTree
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183Minimum Stability Factor of ArrayHard
ArrayMathBinary Search
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184Minimum Time to Collect All Apples in a TreeMedium
Hash TableTreeDepth-First Search
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185Most Frequent Subtree SumMedium
Hash TableTreeDepth-First Search
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186Most Profitable Path in a TreeMedium
ArrayTreeDepth-First Search
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187Move Sub-Tree of N-Ary TreeHard
TreeDepth-First Search
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188My Calendar IMedium
ArrayBinary SearchDesign
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189My Calendar IIMedium
ArrayBinary SearchDesign
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190My Calendar IIIHard
Binary SearchDesignSegment Tree
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191N-ary Tree Level Order TraversalMedium
TreeBreadth-First Search
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192N-ary Tree Postorder TraversalEasy
StackTreeDepth-First Search
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193N-ary Tree Preorder TraversalEasy
StackTreeDepth-First Search
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194Number of Good Leaf Nodes PairsMedium
TreeDepth-First SearchBinary Tree
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195Number of Good PathsHard
ArrayHash TableTree
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196Number of Nodes in the Sub-Tree With the Same LabelMedium
Hash TableTreeDepth-First Search
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197Number of Nodes With Value OneMedium
ArrayTreeDepth-First Search
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198Number of Pairs Satisfying InequalityHard
ArrayBinary SearchDivide and Conquer
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199Number of Subarrays With AND Value of KHard
ArrayBinary SearchBit Manipulation
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200Number Of Ways To Reconstruct A TreeHard
ArrayHash TableTree
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201Online Majority Element In SubarrayHard
ArrayBinary SearchDesign
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202Operations on TreeMedium
ArrayHash TableTree
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203Optimize Water Distribution in a VillageHard
Union-FindGraph TheoryHeap (Priority Queue)
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204Path In Zigzag Labelled Binary TreeMedium
MathTreeBinary Tree
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205Path Sum IIMedium
BacktrackingTreeDepth-First Search
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206Path Sum IIIMedium
TreeDepth-First SearchBinary Tree
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207Path Sum IVMedium
ArrayHash TableTree
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208Path SumEasy
TreeDepth-First SearchBreadth-First Search
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209Peaks in ArrayHard
ArrayBinary Indexed TreeSegment Tree
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210Populating Next Right Pointers in Each Node IIMedium
Linked ListTreeDepth-First Search
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211Populating Next Right Pointers in Each NodeMedium
Linked ListTreeDepth-First Search
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212Print Binary TreeMedium
TreeDepth-First SearchBreadth-First Search
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213Pseudo-Palindromic Paths in a Binary TreeMedium
Bit ManipulationTreeDepth-First Search
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214Pythagorean Distance Nodes in a TreeMedium
TreeBreadth-First Search
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215Queries on a Permutation With KeyMedium
ArrayBinary Indexed TreeSimulation
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216Queue Reconstruction by HeightMedium
ArrayBinary Indexed TreeSegment Tree
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217Range Frequency QueriesMedium
ArrayHash TableBinary Search
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218Range ModuleHard
DesignSegment TreeOrdered Set
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219Range Sum of BSTEasy
TreeDepth-First SearchBinary Search Tree
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220Range Sum Query 2D - MutableMedium
ArrayDesignBinary Indexed Tree
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221Range Sum Query - MutableMedium
ArrayDivide and ConquerDesign
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222Reachable Nodes With RestrictionsMedium
ArrayHash TableTree
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223Recover a Tree From Preorder TraversalHard
StringTreeDepth-First Search
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224Recover Binary Search TreeMedium
TreeDepth-First SearchBinary Search Tree
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225Rectangle Area IIHard
ArraySegment TreeSweep Line
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226Reverse Odd Levels of Binary TreeMedium
TreeDepth-First SearchBreadth-First Search
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227Reverse PairsHard
ArrayBinary SearchDivide and Conquer
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228Root Equals Sum of ChildrenEasy
TreeBinary Tree
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229Same TreeEasy
TreeDepth-First SearchBreadth-First Search
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230Search in a Binary Search TreeEasy
TreeBinary Search TreeBinary Tree
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231Second Minimum Node In a Binary TreeEasy
TreeDepth-First SearchBinary Tree
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232Separate Squares IIHard
ArrayBinary SearchSegment Tree
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233Serialize and Deserialize Binary TreeHard
StringTreeDepth-First Search
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234Serialize and Deserialize BSTMedium
StringTreeDepth-First Search
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235Serialize and Deserialize N-ary TreeHard
StringTreeDepth-First Search
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236Shortest Path in a Weighted TreeHard
ArrayTreeDepth-First Search
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237Smallest Common RegionMedium
ArrayHash TableString
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238Smallest String Starting From LeafMedium
StringBacktrackingTree
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239Smallest Subtree with all the Deepest NodesMedium
Hash TableTreeDepth-First Search
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240Split BSTMedium
TreeBinary Search TreeRecursion
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241Step-By-Step Directions From a Binary Tree Node to AnotherMedium
StringTreeDepth-First Search
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242Subtree of Another TreeEasy
TreeDepth-First SearchString Matching
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243Sum of Beautiful SubsequencesHard
ArrayMathBinary Indexed Tree
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244Sum of Left LeavesEasy
TreeDepth-First SearchBreadth-First Search
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245Sum of Nodes with Even-Valued GrandparentMedium
TreeDepth-First SearchBreadth-First Search
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246Sum of Perfect Square AncestorsHard
ArrayHash TableMath
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247Sum of Root To Leaf Binary NumbersEasy
TreeDepth-First SearchBinary Tree
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248Sum Root to Leaf NumbersMedium
TreeDepth-First SearchBinary Tree
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249Symmetric TreeEasy
TreeDepth-First SearchBreadth-First Search
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250The Skyline ProblemHard
ArrayDivide and ConquerBinary Indexed Tree
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251Throne InheritanceMedium
Hash TableTreeDepth-First Search
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252Time Needed to Inform All EmployeesMedium
TreeDepth-First SearchBreadth-First Search
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253Total Sum of Interaction Cost in Tree GroupsHard
ArrayTreeDepth-First Search
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254Tree DiameterMedium
TreeDepth-First SearchBreadth-First Search
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255Tree of CoprimesHard
ArrayMathTree
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256Trim a Binary Search TreeMedium
TreeDepth-First SearchBinary Search Tree
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257Two Sum BSTsMedium
Two PointersBinary SearchStack
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258Two Sum IV - Input is a BSTEasy
Hash TableTwo PointersTree
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259Univalued Binary TreeEasy
TreeDepth-First SearchBreadth-First Search
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260Validate Binary Search TreeMedium
TreeDepth-First SearchBinary Search Tree
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261Validate Binary Tree NodesMedium
TreeDepth-First SearchBreadth-First Search
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262Verify Preorder Sequence in Binary Search TreeMedium
ArrayStackTree
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263Verify Preorder Serialization of a Binary TreeMedium
StringStackTree
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264Vertical Order Traversal of a Binary TreeHard
Hash TableTreeDepth-First Search
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265Maximum Good Subtree ScoreHard
ArrayDynamic ProgrammingBit Manipulation
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266Maximum Sum of Subsequence With Non-adjacent ElementsHard
ArrayDivide and ConquerDynamic Programming
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