Leetcode Problem 1676. Lowest Common Ancestor of a Binary Tree IV

1676. Lowest Common Ancestor of a Binary Tree IV

Leetcode Solutions

Recursive Post-order Traversal

  1. Convert the array of target nodes into a set for efficient lookup.
  2. Define a recursive function that takes a node as an argument.
  3. If the current node is null or one of the target nodes, return the current node.
  4. Recursively call the function on the left and right children of the current node.
  5. If both calls return non-null values, the current node is the LCA.
  6. If only one of the calls returns a non-null value, propagate that value up the call stack.
  7. If both calls return null, return null.
  8. The initial call to the recursive function with the root node will return the LCA of all target nodes.
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Iterative Pre-order Traversal with Parent Pointers

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