Medium · Trees

N-ary tree diameter

Given the root of an N-ary tree, return its diameter: the number of edges on the longest path between any two nodes (0 for an empty or single-node tree).

Examples

Example 1

{
  "tree": [1, 2, 3, 4, null, 5, null, 6]
}

Output: diameter = 5

Example 2

{
  "nodes": [
    {"val": 1, "children": [1]},
    {"val": 2, "children": [2]},
    {"val": 3, "children": [3]},
    {"val": 4, "children": []}
  ]
}

Output: diameter = 3

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