/* Chapter 11, exercise 15: read file of whitespace-separated numbers, output
 file of numbers using scientific format, precision 8 in four fields of 20
 characters per line
*/

#include "std_lib_facilities.h"

int main() {
	cout << "Enter input file name: ";
	string iname;
	cin >> iname;
	ifstream ifs(iname.c_str());
	if (!ifs) error("can't open input file ", iname);

	// read numbers
	double d;
	vector<double> nums;
	while (ifs >> d)
		nums.push_back(d);

	// print numbers in given format
	cout << scientific << setprecision(8);
	for (int i = 0; i < nums.size(); ++i) {
		cout << setw(20) << nums[i];
		if ((i + 1 )% 4 == 0) cout << endl;
	}

}