Sort Array By Parity

sortArrayByParity.cpp

class Solution {
public:
    vector<int> sortArrayByParity(vector<int>& A) {
        int back = A.size() - 1;
        for (int i = 0; i < back; ++i) {
            if (A[i] % 2 == 1) {
                std::swap(A[back], A[i]);
                back--;
                i--;
            }
        }
        return A;
    }
};