※ 引述《smart0eddie (smart0eddie)》之銘言：
: 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.
: 原本想說這題很簡單啊
: 所有node算一下誰的edge最多
: 然後時間跟別人比慢的要死
: 一看答案
: 靠北 直接取兩個edge 共通的node就好了
: 泥板只剩我不看答案連easy都不會了
思路:
哈希表紀錄node出現次數 出現兩次就是交點
Python Code:
class Solution:
def findCenter(self, edges: List[List[int]]) -> int:
record = defaultdict(int)
for i in range(len(edges)):
record[edges[i][0]] += 1
record[edges[i][1]] += 1
if record[edges[i][0]] == 2:
return edges[i][0]
if record[edges[i][1]] == 2:
return edges[i][1]
我本來想說要建圖 後來想想找到出現兩次的就好了