1.题目:
In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated...N times....例一:
Input: [1,2,3,3]
Output: 3
例二:
Input: [2,1,2,5,3,2]
Output: 2
注意:
4 <= A.length <= 10000
0 N-Repeated Element in Size 2N Array...Memory Usage: 14.3 MB, less than 5.12% of Python3 online submissions for N-Repeated Element in Size 2N