• 0100 - Same Tree
• 0101 - Symmetric Tree
• 0102 - Binary Tree Level Order Traversal
• 0103 - Binary Tree Zigzag Level Order Traversal
• 0104 - Maximum Depth of Binary Tree
• 0112 - Path Sum
• 0617 - Merge Two Binary Trees
• 0637 - Average of Levels in Binary Tree
• 0965 - Univalued Binary Tree
• 1091 - Shortest Path in Binary Matrix