Recently did my phone screen for London location. Below two questions were asked-\n\n1) https://leetcode.com/problems/buildings-with-an-ocean-view/\n2) https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree-iii/\n\nI solved the second question with O(N) space which can be done in O(1).  I realised it after solving the problem. Hence got rejected. :(\n\nAdding my solution for reference:\n\n```\npublic Node LCA(Node a, Node b) {\n        Set<Integer> nodes = new HashSet<>();\n        while (a != null) {\n            nodes.add(a.val);\n            a = a.parent;\n        }\n        while (b != null) {\n            if (nodes.contains(b.val)) return b;\n            b = b.parent;\n        }\n        return b;\n    }\n```\n

Recently did my phone screen for London location. Below two questions were asked-\n\n1) https://leetcode.com/problems/buildings-with-an-ocean-view/\n2) https://