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261 problems

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Array2,209 String870 Hash Table786 Math682 Dynamic Programming666 Sorting504 Greedy480 Binary Search352 Depth-First Search335 Database303 Bit Manipulation283 Matrix278 Tree261 Breadth-First Search255 Two Pointers249 All topics

With video · 261 results

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TitleSolutionAcceptDifficultyTopics

94. Binary Tree Inorder TraversalVideo

Solution80.4%Easy

Binary Tree, Depth-First Search +2· 7 companies

95. Unique Binary Search Trees IIVideo

Solution63.3%Medium

Backtracking, Binary Search Tree +3· 5 companies

96. Unique Binary Search TreesVideo

Solution64.0%Medium

Binary Search Tree, Binary Tree +3· 10 companies

98. Validate Binary Search TreeVideo

Solution36.1%Medium

Binary Search Tree, Binary Tree +2· 18 companies

99. Recover Binary Search TreeVideo

Solution60.9%Medium

Binary Search Tree, Binary Tree +2· 8 companies

100. Same TreeVideo

Solution68.0%Easy

Binary Tree, Breadth-First Search +2· 9 companies

101. Symmetric TreeVideo

Solution62.1%Easy

Binary Tree, Breadth-First Search +2· 11 companies

102. Binary Tree Level Order TraversalVideo

Solution73.5%Medium

Binary Tree, Breadth-First Search +1· 16 companies

103. Binary Tree Zigzag Level Order TraversalVideo

Solution64.4%Medium

Binary Tree, Breadth-First Search +1· 19 companies

104. Maximum Depth of Binary TreeVideo

Solution78.6%Easy

Binary Tree, Breadth-First Search +2· 17 companies

105. Construct Binary Tree from Preorder and Inorder TraversalVideo

Solution69.7%Medium

Array, Binary Tree +3· 9 companies

106. Construct Binary Tree from Inorder and Postorder TraversalVideo

Solution69.4%Medium

Array, Binary Tree +3· 7 companies

107. Binary Tree Level Order Traversal IIVideo

Solution69.0%Medium

Binary Tree, Breadth-First Search +1· 6 companies

108. Convert Sorted Array to Binary Search TreeVideo

Solution75.9%Easy

Array, Binary Search Tree +3· 9 companies

109. Convert Sorted List to Binary Search TreeVideo

Solution67.4%Medium

Binary Search Tree, Binary Tree +3· 9 companies

110. Balanced Binary TreeVideo

Solution59.2%Easy

Binary Tree, Depth-First Search +1· 9 companies

111. Minimum Depth of Binary TreeVideo

Solution53.7%Easy

Binary Tree, Breadth-First Search +2· 7 companies

112. Path SumVideo

Solution55.8%Easy

Binary Tree, Breadth-First Search +2· 9 companies

113. Path Sum IIVideo

Solution62.6%Medium

Backtracking, Binary Tree +2· 10 companies

114. Flatten Binary Tree to Linked ListVideo

Solution71.6%Medium

Binary Tree, Depth-First Search +3· 8 companies

116. Populating Next Right Pointers in Each NodeVideo

Solution67.6%Medium

Binary Tree, Breadth-First Search +3· 8 companies

117. Populating Next Right Pointers in Each Node IIVideo

Solution57.9%Medium

Binary Tree, Breadth-First Search +3· 7 companies

124. Binary Tree Maximum Path SumVideo

Solution42.7%Hard

Binary Tree, Depth-First Search +2· 25 companies

129. Sum Root to Leaf NumbersVideo

Solution70.3%Medium

Binary Tree, Depth-First Search +1· 7 companies

144. Binary Tree Preorder TraversalVideo

Solution76.6%Easy

Binary Tree, Depth-First Search +2· 5 companies

145. Binary Tree Postorder TraversalVideo

Solution79.0%Easy

Binary Tree, Depth-First Search +2· 5 companies

156. Binary Tree Upside DownVideoPremium

Solution65.4%Medium

Binary Tree, Depth-First Search +1· 2 companies

173. Binary Search Tree IteratorVideo

Solution76.9%Medium

Binary Search Tree, Binary Tree +4· 8 companies

199. Binary Tree Right Side ViewVideo

Solution71.5%Medium

Binary Tree, Breadth-First Search +2· 14 companies

222. Count Complete Tree NodesVideo

Solution72.6%Medium

Binary Search, Binary Tree +2· 7 companies

226. Invert Binary TreeVideo

Solution80.5%Easy

Binary Tree, Breadth-First Search +2· 9 companies

230. Kth Smallest Element in a BSTVideo

Solution77.2%Medium

Binary Search Tree, Binary Tree +2· 12 companies

235. Lowest Common Ancestor of a Binary Search TreeVideo

Solution71.4%Medium

Binary Search Tree, Binary Tree +2· 10 companies

236. Lowest Common Ancestor of a Binary TreeVideo

Solution70.1%Medium

Binary Tree, Depth-First Search +1· 22 companies

250. Count Univalue SubtreesVideoPremium

Solution57.5%Medium

Binary Tree, Depth-First Search +1· 4 companies

255. Verify Preorder Sequence in Binary Search TreeVideoPremium

Solution51.7%Medium

Array, Binary Search Tree +5· 5 companies

257. Binary Tree PathsVideo

Solution69.5%Easy

Backtracking, Binary Tree +3· 8 companies

270. Closest Binary Search Tree ValueVideoPremium

Solution49.2%Easy

Binary Search, Binary Search Tree +3· 7 companies

272. Closest Binary Search Tree Value IIVideoPremium

Solution61.1%Hard

Binary Search Tree, Binary Tree +5· 3 companies

285. Inorder Successor in BSTVideoPremium

Solution51.2%Medium

Binary Search Tree, Binary Tree +2· 6 companies

297. Serialize and Deserialize Binary TreeVideo

Solution61.1%Hard

Binary Tree, Breadth-First Search +4· 23 companies

298. Binary Tree Longest Consecutive SequenceVideoPremium

Solution54.7%Medium

Binary Tree, Depth-First Search +1· 4 companies

314. Binary Tree Vertical Order TraversalVideoPremium

Solution57.8%Medium

Binary Tree, Breadth-First Search +4· 9 companies

331. Verify Preorder Serialization of a Binary TreeVideo

Solution47.8%Medium

Binary Tree, Stack +2· 1 company

333. Largest BST SubtreeVideoPremium

Solution45.8%Medium

Binary Search Tree, Binary Tree +3· 2 companies

337. House Robber IIIVideo

Solution56.3%Medium

Binary Tree, Depth-First Search +2· 13 companies

341. Flatten Nested List IteratorVideo

Solution65.6%Medium

Depth-First Search, Design +4· 19 companies

366. Find Leaves of Binary TreeVideoPremium

Solution81.4%Medium

Binary Tree, Depth-First Search +1· 6 companies

404. Sum of Left LeavesVideo

Solution63.1%Easy

Binary Tree, Breadth-First Search +2· 6 companies

426. Convert Binary Search Tree to Sorted Doubly Linked ListVideoPremium

Solution65.2%Medium

Binary Search Tree, Binary Tree +5· 4 companies

Showing 1–50 of 261