283. Move Zeroes

Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements.
For example, given nums = [0, 1, 0, 3, 12], after calling your function, nums should be [1, 3, 12, 0, 0].
Note:
You must do this in-place without making a copy of the array.
Minimize the total number of operations.

Solution：Two pointers

思路：
Time Complexity: O(N) Space Complexity: O(1)

Solution Code：

class Solution {
    public void moveZeroes(int[] nums) {
        int new_i = 0;
        for(int i = 0; i < nums.length; i++) {
            if(nums[i] != 0) nums[new_i++] = nums[i];
        }
        
        // fill the rest with zero
        while (new_i < nums.length) {
            nums[new_i++] = 0;
        }
        
    }
}