← Roadmaps all trees problems

🌳

Trees

Traversals, depth, paths, BST, ancestors.

5 subtopics · 92 problems0/60 on the path solved

next ▸ Inorder Traversalmachine 1050

01

Traversals

0/16 of 31

Inorder, preorder, postorder, level order.

○Inorder TraversalSilver · 1050 ○Preorder TraversalSilver · 1050 ○Serialize Tree to Level OrderSilver · 1050 ○Inorder Traversal ArraySilver · 1050 ○Preorder Traversal ArraySilver · 1080 ○Postorder TraversalSilver · 1100 ○Binary Tree Inorder TraversalSilver · 1100 ○Binary Tree Preorder TraversalSilver · 1100 ○Postorder Traversal ArraySilver · 1100 ○Binary Tree Right Side ViewSilver · 1150 ○Binary Tree Postorder TraversalGold · 1300 ○Flatten Tree to Linked ListGold · 1340 ○Binary Tree Level Order TraversalGold · 1350 ○Level Order Array of ArraysGold · 1350 ○Zigzag Level Order TraversalGold · 1380 ○Kth Smallest in a BSTGold · 1380 + 15 more in the arena →

02

Depth & shape

0/16 of 25

Max/min depth, balanced, symmetric, diameter.

○Count NodesSilver · 1000 ○Count Nodes in Binary TreeSilver · 1000 ○Same TreeSilver · 1100 ○Is Height-BalancedSilver · 1200 ○Count Nodes in RangeSilver · 1200 ○All Elements in Two BSTsGold · 1320 ○Invert Binary TreeGold · 1350 ○Sorted List to Balanced BSTGold · 1360 ○Invert TreeGold · 1380 ○Sorted Array to BSTGold · 1400 ○Merge Two Binary TreesGold · 1400 ○Invert a Binary TreeGold · 1400 ○Is the Tree Height-Balanced?Gold · 1410 ○Symmetric TreeGold · 1450 ○Balanced Binary TreeGold · 1450 ○Balance a BST (Return Height)Gold · 1450 + 9 more in the arena →

03

Sums & paths

0/16 of 24

Path sum, root-to-leaf, left leaves, good nodes.

○Sum of Left LeavesSilver · 1100 ○Count LeavesSilver · 1150 ○Average of LevelsSilver · 1150 ○Deepest Leaves SumGold · 1300 ○Has Root-to-Leaf Path SumGold · 1300 ○Average of Levels in Binary TreeGold · 1300 ○Count Good NodesGold · 1330 ○Sum Root to Leaf NumbersGold · 1340 ○Sum of NodesGold · 1350 ○Average of Levels ArrayGold · 1350 ○Path SumGold · 1400 ○Path Sum IIGold · 1400 ○Path Sum ExistsGold · 1400 ○Path Sum II CountGold · 1420 ○Path Sum CountGold · 1500 ○Path Sum III CountGold · 1500 + 8 more in the arena →

04

BST

0/6

Validate, range sum, kth smallest, LCA in BST.

○Increasing Order TraversalSilver · 1080 ○Search BSTSilver · 1200 ○Kth Smallest Element in a BSTGold · 1300 ○Increasing Order Search TreeGold · 1320 ○Validate BSTGold · 1450 ○Kth Smallest in BSTGold · 1550

05

Ancestors & misc

0/6

LCA, subtree, cameras, flatten.

○Lowest Common Ancestor in a BSTGold · 1340 ○Lowest Common Ancestor in BSTGold · 1350 ○Lowest Common AncestorPlatinum · 1750 ○Lowest Common Ancestor of a Binary TreePlatinum · 1750 ○Is SubtreePlatinum · 1760 ○Binary Tree CamerasDiamond · 1900