题目：原题链接（简单）
标签：数组
解法 | 时间复杂度 | 空间复杂度 | 执行用时 |
Ans 1 (Python) | O(N) | O(N) | 40ms (83.01%) |
Ans 2 (Python) | O(N) | O(N) | 36ms (94.12%) |
Ans 3 (Python) |
解法一（双集合）：
def destCity(self, paths: List[List[str]]) -> str:
maybe = set()
wrong = set()
for path in paths:
wrong.add(path[0])
maybe.add(path[1])
return (maybe - wrong).pop()解法二（增加跳出循环，提高效率）：
def destCity(self, paths: List[List[str]]) -> str:
paths = list(zip(*paths))
wrong = set(paths[0])
for path in paths[1]:
if path not in wrong:
return path
