Move all even numbers to left, odd numbers to right

main.cpp

#include <iostream>
#include <vector>

using namespace std;
/*
Chuyển số chẵn về bên trái, số lẻ về bên phải
http://algorithms.tutorialhorizon.com/separate-even-and-odd-integers-in-a-given-array/
int [] arrA = {1,2,3,4,6,8,7,12};
Output: [12, 2, 8, 4, 6, 3, 7, 1]
*/
int main() {
    vector<int> arr = {9, 10, 1, 2, 3, 4, 6, 8, 7, 12};
    auto left = arr.begin();
    auto right = arr.end() - 1;
    while (left < right) {

        if (*left % 2 == 0) {

            left++;
        } else if (*right % 2 == 0) {

            auto temp = *left;
            *left = *right;
            *right = temp;
        }
        if (*right % 2 == 1) {

            right--;
        }
    }
    for (auto i: arr) {
        cout << i << " ";
    }
    return 0;
}