2460-apply-operations-to-an-array.js

/**
 * 2460. Apply Operations to an Array
 * https://leetcode.com/problems/apply-operations-to-an-array/
 * Difficulty: Easy
 *
 * You are given a 0-indexed array nums of size n consisting of non-negative integers.
 *
 * You need to apply n - 1 operations to this array where, in the ith operation (0-indexed),
 * you will apply the following on the ith element of nums:
 * - If nums[i] == nums[i + 1], then multiply nums[i] by 2 and set nums[i + 1] to 0.
 *   Otherwise, you skip this operation.
 *
 * After performing all the operations, shift all the 0's to the end of the array.
 * - For example, the array [1,0,2,0,0,1] after shifting all its 0's to the end, is [1,2,1,0,0,0].
 *
 * Return the resulting array.
 *
 * Note that the operations are applied sequentially, not all at once.
 */

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var applyOperations = function(nums) {
  for (let i = 0; i < nums.length - 1; i++) {
    if (nums[i] === nums[i + 1]) {
      nums[i] *= 2;
      nums[i + 1] = 0;
    }
  }
  return [...nums.filter(n => n), ...nums.filter(n => !n)];
};