/**
 * Time O(N) | Space O(1)
 * @param {number[]} nums
 * @param {number} val
 * @return {number}
 */
var removeElement = function (nums, val) {
    let ptr1 = nums.length - 2;
    let ptr2 = nums.length - 1;

    if (!nums) return 0;
    if (nums.length === 1) {
        if (nums[0] === val) return 0;
        return 1;
    }

    while (ptr1 > -1) {
        if (nums[ptr2] === val) {
            ptr2--;

            while (nums[ptr1] === val) {
                ptr2--;
                ptr1--;
            }
        } else if (nums[ptr1] === val) {
            let temp = nums[ptr1];
            nums[ptr1] = nums[ptr2];
            nums[ptr2] = temp;
            ptr2--;
        }

        ptr1--;
    }

    return ptr2 + 1;
};

/**
 * @param {number[]} nums
 * @param {number} val
 * @return {number}
 */
var removeElement = function (nums, val) {
    for (let i = 0; i < nums.length; i++) {
        if (nums[i] === val) {
            nums.splice(i, 1);
            i--;
        }
    }

    return nums.length;
};