# prices times weights

Bjarne Stroustrup “Programming Principles and Practice Using C++”
Chapter 8 Exercise 9
Using std_lib_facilities.h by Bjarne Stroustrup.

main.cpp main file

[code language=”cpp”]
// Philipp Siedler
// Bjarne Stroustrup’s PP
// Chapter 8 Exercise 9

#include "std_lib_facilities.h"

vector<double> price;
vector<double> weight;

class indexCalc {
vector<double> p;
vector<double> w;

public:
indexCalc(vector<double> _p, vector<double> _w) :p(_p), w(_w) { };
void calculate();
};

while (cin) {
char priceChar;
double priceDouble;
cin.get(priceChar);
if (isspace(priceChar)) {
if (priceChar == ‘\n’) {
break;
}
}
cin.unget();
cin >> priceDouble;
p.push_back(priceDouble);
}
}

while (p.size() != w.size()) {
char weightChar;
double weightDouble;
cin.get(weightChar);
if (isspace(weightChar)) {
if (weightChar == ‘\n’ && p.size() == w.size()) {
break;
}
}
cin.unget();
cin >> weightDouble;
w.push_back(weightDouble);
}
}

void indexCalc::calculate() {
double index = 0;
for (int i = 0; i < p.size(); i++) {
index += p[i] * w[i];
}
cout << index << "\n";
}

int main()
try
{
indexCalc ic(price, weight);

cout << "Enter prices\n";

cout << "Enter weights\n";

ic.calculate();

keep_window_open();
}

catch (runtime_error e) {
cout << e.what() << "\n";
keep_window_open();
}

catch (…) {
cout << "Exiting\n";
keep_window_open();
}
[/code]

```Output:
Enter prices
23 24 25 53 32
Enter weights
3 4 5 3 4
577
Please enter a character to exit
```