leetcode 26 remove duplicates from sorted array

import java.util.Arrays;

public class Solution1 {
    // 时间复杂度O(N)  空间复杂度O(1)   双指针
    public static int removeDuplicates(int[] nums) {
        if (nums == null || nums.length == 0) {
            return 0;
        }

        int slow = 0;                 // [0,slow]  存放合法数据(答案)
        // 快指针遍历数组
        for (int fast = 0; fast < nums.length; ++fast) {
            // 当前元素在[0,slow]中未出现，添加到[0,slow)  此处体会数组有序这个条件
            if (nums[slow] != nums[fast]) {
                nums[++slow] = nums[fast];
            }
        }
        return slow + 1;
    }

    public static void main(String[] args) {
        int[] nums = {0, 0, 1, 1, 1, 2, 2, 3, 3, 4};
        System.out.println(removeDuplicates(nums));
        System.out.println(Arrays.toString(nums));
    }
}