Majority Element - LeetCode : Swift

Majority Element - LeetCode

Given an array nums of size n, return the majority element.

The majority element is the element that appears more than [n / 2] times. You may assume that the majority element always exists in the array.

Example 1:

Input: nums = [3,2,3]
Output: 3

Example 2:

Input: nums = [2,2,1,1,1,2,2]
Output: 2

Constraints:

• n == nums.length
• 1 <= n <= 5 * 10^4
• -10^9 <= nums[i] <= 10^9

Follow-up: Could you solve the problem in linear time and in O(1) space?

Solution

class Solution {
    func majorityElement(_ nums: [Int]) -> Int {
        var maj = nums[0], count = 0

        for num in nums {
            if num == maj {
                count += 1
            } else {
                maj = (count - 1) != 0 ? maj : num
                count -= (count - 1) != 0 ? 1 : 0
            }
        }
        return maj
    }
}