#include <functional>
#include <numeric>
#include <iostream>

int main()
{
  double arr[] = { 1, 2, 3, 4, 5 };
  double sum[5]; 

  std::transform_exclusive_scan(arr, arr+5, sum, 100, std::plus{}, [](auto x){ return x*x; });

  for (double d : sum)
  {
    std::cout << d << ' ';
  }
  std::cout << '\n';   
}