FindCenterOfStarGraph.cpp

// Source : https://leetcode.com/problems/find-center-of-star-graph/
// Author : Hao Chen
// Date   : 2021-03-19

/***************************************************************************************************** 
 *
 * 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
 * 
 * Constraints:
 * 
 * 	3 <= n <= 105
 * 	edges.length == n - 1
 * 	edges[i].length == 2
 * 	1 <= ui, vi <= n
 * 	ui != vi
 * 	The given edges represent a valid star graph.
 ******************************************************************************************************/