Day 14.2.txt

1791. Find Center of Star Graph

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.



class Solution {
    public int findCenter(int[][] e) {
        if(e[0][1]==e[1][0])
            return e[0][1];
        else if(e[0][1]==e[1][1])
            return e[0][1];
        else if(e[0][0]==e[1][1])
            return e[0][0];
        else
            return e[0][0];
    }
}