majority-element.js

/**
 * Majority Elements
 *
 * Given an array of size n, find the majority element. The majority element is the element that appears
 * more than ⌊ n/2 ⌋ times.
 *
 * You may assume that the array is non-empty and the majority element always exist in the array.
 *
 * Example 1:
 *
 * Input: [3,2,3]
 * Output: 3
 *
 * Example 2:
 *
 * Input: [2,2,1,1,1,2,2]
 * Output: 2
 */

/**
 * @param {number[]} nums
 * @return {number}
 */
const majorityElement = nums => {
  let major = nums[0];
  let count = 1;

  for (let i = 1; i < nums.length; i++) {
    if (count === 0) {
      count++;
      major = nums[i];
    } else if (major === nums[i]) {
      count++;
    } else {
      count--;
    }
  }

  return major;
};

export { majorityElement };