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 <= 10^5edges.length == n - 1edges[i].length == 21 <= ui, vi <= nui != vi- The given
edgesrepresent 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
}