Problem: 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.

Solution:

class Solution {
public:
    void moveZeroes(vector<int>& nums) {
        int nonZeroPtr = 0;
        for (int i = 0; i < nums.size(); i++) {
            if (nums[i] != 0) {
                nums[nonZeroPtr++] = nums[i];
            }
        }

        for (int j = nonZeroPtr; j < nums.size(); j++) {
            nums[j] = 0;
        }
    }
};