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.

C++(16ms):

 1 class Solution {
 2 public:
 3     void moveZeroes(vector<int>& nums) {
 4         int j = 0 ;
 5         for (int i = 0; i < nums.size();i++ ){
 6             if (nums[i] != 0 ){
 7                 nums[j] = nums[i];
 8                 j++;
 9             }
10         }
11         for (; j <nums.size() ; j++){
12             nums[j] = 0 ;
13         }
14     }
15 };

C++(19ms):

 1 class Solution {
 2 public:
 3     void moveZeroes(vector<int>& nums) {
 4         int j = 0 ;
 5         for (int i = 0; i < nums.size();i++ ){
 6             if (nums[i] != 0 ){
 7                 swap(nums[j],nums[i]);
 8                 j++;
 9             }
10         }
11     }
12 };