find-center-of-star-graph_1791.py

# There is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly n - 1 edges that connect the center node with every other node.

# You are given a 2D integer array edges where each edges[i] = [ui, vi] indicates that there is an edge between the nodes ui and vi. Return the center of the given star graph.


# Example 1:

# 
# Input: edges = [[1,2],[2,3],[4,2]]
# Output: 2
# Explanation: As shown in the figure above, node 2 is connected to every other node, so 2 is the center.
# Example 2:

# Input: edges = [[1,2],[5,1],[1,3],[1,4]]
# Output: 1

# ---------------------------------------Runtime 772 ms Beats 28.21% Memory 59.1 MB Beats 5.47%---------------------------------------

from typing import List


class Solution:
    def findCenter(self, edges: List[List[int]]) -> int:
        edges_set = list(map(set, edges))
        res = 0
        for index in range(len(edges_set) - 1):
            res = edges_set[index] & edges_set[index + 1]
        return res.pop()