题解 | #数组中重复的数字#

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param numbers int整型一维数组 
# @return int整型
#
class Solution:
    def duplicate(self , numbers: List[int]) -> int:
        # write code here
        from collections import Counter
        #创建 Counter 字典对象
        cout = Counter(numbers)
        for key, val in cout.items():
            if val > 1:
                return(key)
        return -1