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.

 Runtime: 60ms

class Solution {
public:
    void moveZeroes(vector<int>& nums) {
        if(nums.size() <= 1) return;
        
        int zr = 0, nzr = 0;
        while(zr < nums.size()){
            while(zr < nums.size() && nums[zr] != 0)
                zr++;
            nzr = zr + 1;
            while(nzr < nums.size() && nums[nzr] == 0)
                nzr++;
            
            if(nzr >= nums.size()) break;
            swap(nums[zr], nums[nzr]);
            zr++;
            nzr++;
        }
    }
};