LeetCode : 27. Remove Element

[congr]

https://leetcode.com/problems/remove-element/

[congr]

My first naive code(AC) - O(N)

class Solution {
    public int removeElement(int[] nums, int val) {
        int left = 0, right = nums.length-1;
        while (left <= right) { // !!! [2] case
            while (left < nums.length && nums[left] != val) left++;
            while (right >= 0 && nums[right] == val) right--;

            if (left >= right) return left; // !!

            int temp = nums[left];
            nums[left] = nums[right];
            nums[right] = temp;
        }

        return left;
    }
}

[congr]

A lot shorter code

class Solution {
    public int removeElement(int[] nums, int val) {
        int k = 0;

        for (int i = 0; i < nums.length; i++)
            if (nums[i] != val) nums[k++] = nums[i];

        return k;
    }
}