existing list - https://leetcode.com/discuss/interview-question/256347/ctci-questions-lists\n\nTrees and Graphs :-\n\n  **Validate BST**  https://leetcode.com/problems/validate-binary-search-tree/\n\n  **Successor** https://leetcode.com/problems/inorder-successor-in-bst-ii/ ,  similar - https://leetcode.com/problems/inorder-successor-in-bst/\n\n  **Build Order** https://leetcode.com/problems/course-schedule/\n\n **First common ancestor**  https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/\n\n **BST Sequence** similar https://leetcode.com/problems/unique-binary-search-trees-ii/\n\n **Check Subtree** https://leetcode.com/problems/subtree-of-another-tree/\n \n**Path with Sum** 1) https://leetcode.com/problems/path-sum/  2)  https://leetcode.com/problems/binary-tree-paths/\n\nI will keep updating this list.  please comment if you found any questions\n

existing list - https://leetcode.com/discuss/interview-question/256347/ctci-questions-lists\n\nTrees and Graphs :-\n\n  Validate BST  https://leetcode.com/probl