#include <iostream>
#include <functional>
#include <algorithm>
#include <vector>
 
int main() {
    std::vector<int> v1 { 1, 2, 3, 4 };
    const std::vector<int> v2 { -1, 2, -1, 2 };
    std::transform(begin(v1), end(v1), begin(v2), begin(v1), std::multiplies<int>());
    for (auto i: v1) std::cout << i << ' ';
    std::cout << std::endl;
}