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Majority Element

Problem statement​

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 * 104
  • -231 <= nums[i] <= 231 - 1
Follow-up: Could you solve the problem in linear time and in O(1) space?

My solution​

/**
 * @param {number[]} nums
 * @return {number}
 */
var majorityElement = function(nums) {
    const memo = new Map();
    
    for (const num of nums) {
        memo.set(num, (memo.get(num) || 0) + 1)
    }
    
    
    let currentMax = [-1, Number.MIN_SAFE_INTEGER]
    
    for (const [key, value] of memo.entries()) {
        const localMax = Math.max(value, currentMax[1]);
        if (localMax > currentMax[1]) {
            currentMax = [key, value]
        }
    }
    
    return currentMax[0]
};