#include <iostream>

#include <vector>

using namespace std;

class Solution {

public:

vector<int> sortArrayByParity(vector<int>& nums) {

if (nums.size() < 2) return nums;

auto afterEven = nums.begin();

while (*afterEven % 2 == 0 && afterEven != nums.end()) afterEven += 1;

auto it = afterEven;

if (it == nums.end()) return nums;

while (it != nums.end()) {

if (*it % 2 == 0) {

swap(*it, *afterEven);

afterEven += 1;

}

it += 1;

}

return nums;

}

};

int main() {

Solution sol;

vector<int> testArr = {0, 2};

auto res = sol.sortArrayByParity(testArr);

for (auto i : res) {

cout << i << ' ';

}

return 0;

}