#include <iostream>
#include <iterator>
#include <numeric>

int main() {

    int arr[5] = {100};

    std::partial_sum(arr, std::end(arr), arr,
                     [](int a, int b) {
                        return a - 20;
                     });

    for (auto n : arr)
        std::cout << n << std::endl;
}