#include <algorithm>
#include <vector>
#include <iostream>

using namespace std ;
// Free function to double an integer
int double_value(int i)
{
    return i * 2;
}

int main() {
    vector<int> input = {1, 2, 3, 4, 5};
    vector<int> output(input.size());

    // Apply double_value to each element of input and store in output
    transform(input.begin(), input.end(), output.begin(), double_value);

    for (int val : output) {
        cout << val << " "; // Output: 2 4 6 8 10
    }
    cout << endl;

    return 0;
}