Pythagorean Distance Nodes in a Tree

Description

You are given an integer n and an undirected tree with n nodes numbered from 0 to n - 1. The tree is represented by a 2D array edges of length n - 1, where edges[i] = [ui, vi] indicates an undirected edge between ui and vi.

You are also given three distinct target nodes x, y, and z.

For any node u in the tree:

- Let dx be the distance from u to node x

- Let dy be the distance from u to node y

- Let dz be the distance from u to node z

The node u is called special if the three distances form a Pythagorean Triplet.

Return an integer denoting the number of special nodes in the tree.

A Pythagorean triplet consists of three integers a, b, and c which, when sorted in ascending order, satisfy a2 + b2 = c2.

The distance between two nodes in a tree is the number of edges on the unique path between them.