- Binary Tree Inorder Traversal
- Symmetric Tree
- Find Duplicate Subtrees
- Number of Good Components
- Minimum Distance Between BST Nodes
- Minimum Absolute Difference in BST
- Good Stones
- Geeks Island
- Minimum Fuel Cost to Report to the Capital
- Maximum Bipartite Matching
- Select Nodes
- Concatenated Words
- Cheapest Flights Within K Stops
- Find Closest Node to Given Two Nodes
- Populating Next Right Pointers in Each Node II
- Find Bottom Left Tree Value
- Unit Area of largest region of 1's
- Strongly Connected Components (Kosaraju's Algo)
- Mother Vertex
- Minimum Swaps to Sort
- Topological sort
- Find whether path exist
- Find the number of islands
- DFS of Graph
- Detect cycle in an undirected graph
- Detect cycle in an directed graph
- Course Schedule
- Maximum Depth of Binary Tree
- All Elements in Two Binary Search Trees
- Maximum Difference Between Node and Ancestor
- Course Schedule II
- Range Sum of BST
- Jump Game III
- Same Tree
- Binary Tree Tilt
- House Robber III
- Sum of Left Leaves
- Sum Root to Leaf Numbers
- Path Sum II
- Invert Binary Tree
- Path Sum
- Surrounded Regions
- Count Complete Tree Nodes
- Cousins in Binary Tree
- Path Sum III
- Diameter of Binary Tree
- Robot Factory
- Populating Next Right Pointers in Each Node
- Merge Two Binary Trees
- Number of Islands
- Max Area of Island
- Flood Fill
- Find All Groups of Farmland
- Count Sub Islands