[Leetcode]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:

1. You must do this in-place without making a copy of the array.
2. Minimize the total number of operations.

 

Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.

 

思路：整个过程是个不停交换的过程，把非0的数和 0 交换位置。时间要求为O(n)，代码如下

 

class Solution {
    public void moveZeroes(int[] nums) {
        int position = 0;                   //把非0的数换到这位置上
        for (int i=0;i<nums.length;i++){
            if (nums[i]!=0){
                int tmp = nums[position];
                nums[position++] = nums[i];
                nums[i] = tmp;
            }
        }
    }
}