//
// Example of using STL inner_product:  compute vector length.
//
#include <iostream.h>
#include <stdlib.h>             // has EXIT_SUCCESS
#include <numeric>		// has inner_product()
#include <vector>

int main(void) {

  cout << "Enter some numbers, ctrl-D to end:\n";
  vector<double> v;
  double temp;

  while (cin >> temp)
    v.push_back(temp);

  cout << "vector length = "
       << sqrt(inner_product(v.begin(), v.end(), v.begin(), 0.0))
       << endl;

  return EXIT_SUCCESS;
}