majorityElement.js

////////////////////////////////////////////////Majority Element/////////////////////////////////////////////
// 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?
/**
 * @param {number[]} nums
 * @return {number}
 */
 const majorityElement = function(nums) {
    const count = {};
    nums.forEach(i => count[i] = (count[i] || 0) + 1);
    let res = Object.keys(count).reduce((a, b) => count[a] > count[b] ? a : b);
    
    return res;
};

// console.log(majorityElement([3,2,3]));
// console.log(majorityElement([2,2,1,1,1,2,2]));
// console.log(majorityElement([3,3,4]));