1791. Find Center of Star Graph
Easy
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 <= 10^5
edges.length == n - 1
edges[i].length == 2
1 <= ui, vi <= n
ui != vi
- The given
edges
represent a valid star graph.
func findCenter(edges [][]int) int {
n := len(edges)
indegree := make([]int, n + 1)
for _, edge := range edges {
indegree[edge[0] - 1]++
indegree[edge[1] - 1]++
if indegree[edge[0] - 1] == n {
return edge[0]
}
if indegree[edge[1] - 1] == n {
return edge[1]
}
}
return 0
}