LeetCode Algorithm 997. 找到小镇的法官

Posted 2022-06-13 Alex_996

题目链接：997. 找到小镇的法官

Ideas

算法：计数
数据结构：图
思路：统计每个节点的入度和出度，入度为n-1，出度为0的节点即为小镇法官。

Code

Python

from collections import Counter
from typing import List


class Solution:
	def findJudge(self, n: int, trust: List[List[int]]) -> int:
		ans, in_degree, out_degree = -1, Counter(), Counter()
		for (start, end) in trust:
			in_degree[end] += 1
			out_degree[start] += 1
		for i in range(1, n + 1):
			if in_degree[i] == n - 1 and out_degree[i] == 0:
				ans = i
		return ans