Moving Zeros

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.

Find the first 0, exchange it with the first non-zero number from its right part. 

Runtime: 36ms.

 

class Solution {
public:
    void moveZeroes(vector<int>& nums) {
        int n = nums.size();
        if(n <= 1) return;
        
        int left = 0, right = 0;
        while(right < n){
            while(nums[left] != 0) 
                left++; //find the first number equals to 0
            right = left + 1;
            while(nums[right] == 0) //find the first number doesn't equal to 0
                right++;
                
            if(right >= n) return;
            
            swap(nums[left], nums[right]);
            left++;
            right++;
        }
        return;
    }
};