leetcode 283. Move Zeroes

Given an integer array nums, move all 0's to the end of it while maintaining the relative order of the non-zero elements.

Note that you must do this in-place without making a copy of the array.

Example 1:

Input: nums = [0,1,0,3,12]
Output: [1,3,12,0,0]
Example 2:

Input: nums = [0]
Output: [0]

Constraints:

1 <= nums.length <= 104
-231 <= nums[i] <= 231 - 1

class Solution {
    // public void moveZeroes(int[] nums) {
    //     int n = nums.length, left = 0, right = 0;
    //     while (right < n) {
    //         if (nums[right] != 0) {
    //             swap(nums, left, right);
    //             left++;
    //         }
    //         right++;
    //     }
    // }

    // public void swap(int[] nums, int left, int right) {
    //     int temp = nums[left];
    //     nums[left] = nums[right];
    //     nums[right] = temp;
    // }


    // public void moveZeroes(int[] nums) {
    //     int insertPos = 0;
    //     for(int num : nums){
    //         if(num != 0){
    //             nums[insertPos++] = num;
    //         }
    //     }
    //     while(insertPos < nums.length){
    //         nums[insertPos++]=0;
    //     }
    // }    

    public void moveZeroes(int[] nums) {
        if(nums == null || nums.length == 0){
            return;
        }
        int j=0;
        for(int i=0; i<nums.length; ++i){
            if(nums[i] != 0){
                nums[j++] = nums[i];
            }
        }
        for(int i=j; i<nums.length; ++i){
            nums[i] = 0;
        }
    }
}

链接：https://leetcode.cn/problems/move-zeroes