961. N-Repeated Element in Size 2N Array-重复 N 次的元素

In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times.

Return the element repeated N times.

Example 1:
Input: [1,2,3,3]
Output: 3

Example 2:
Input: [2,1,2,5,3,2]
Output: 2

Example 3:
Input: [5,1,5,2,5,3,5,4]
Output: 5

Note:

• 4 <= A.length <= 10000
• 0 <= A[i] < 10000
• A.length is even

Solution in python:

class Solution:
    def repeatedNTimes(self, A: List[int]) -> int:
        adic = dict()
        for item in A:
            if item not in adic.keys():
                adic[item] = 1
            else:
                return item