LeetCode: 961. N-Repeated Element in Size 2N Array / 数组大小为2N的重复元素

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.

理解一下
一个偶数长度的Int数组, 找到重复次数最多的Int值

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

我的解法

class Solution {
    func repeatedNTimes(_ A: [Int]) -> Int {
        var max_num = 1
        var max_count = 1
        var key_Dict = [Int: Int]()
        for i in A {
            if let value = key_Dict[i] {
                let newValue = value + 1
                key_Dict[i] = newValue
                if max_count < newValue {
                    max_count = newValue
                    max_num = i
                }
            } else {
                key_Dict[i] = 1
            }
        }
        return max_num
    }
}

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