0027-remove-element.js

/**
 * 27. Remove Element
 * https://leetcode.com/problems/remove-element/
 * Difficulty: Easy
 *
 * Given an integer array nums and an integer val, remove all occurrences of val in nums in-place.
 * The relative order of the elements may be changed.
 *
 * Since it is impossible to change the length of the array in some languages, you must instead
 * have the result be placed in the first part of the array nums. More formally, if there are
 * k elements after removing the duplicates, then the first k elements of nums should hold the
 * final result. It does not matter what you leave beyond the first k elements.
 *
 * Return k after placing the final result in the first k slots of nums.
 *
 * Do not allocate extra space for another array. You must do this by modifying the input
 * array in-place with O(1) extra memory.
 */

/**
 * @param {number[]} nums
 * @param {number} val
 * @return {number}
 */
var removeElement = function(nums, val) {
  for (let i = nums.length - 1; i > -1; i--) {
    if (nums[i] === val) nums.splice(i, 1);
  }
};