Bjarne Stroustrup “Programming Principles and Practice Using C++”
Chapter 10 Exercise 4.0
Using std_lib_facilities.h by Bjarne Stroustrup.
[code language=”cpp”]
// Philipp Siedler
// Bjarne Stroustrup’s PPP
// Chapter 10 Exercise 4.0
#include "std_lib_facilities.h"
struct Reading {
int hour;
double temperature;
char suffix;
Reading(int h, double t, char s) :hour(h), temperature(t), suffix(s) {}
};
ostream& operator<<(ostream& os, Reading& _temps) {
os << _temps.hour << " " << _temps.temperature << " " << _temps.suffix << endl;
return os;
}
vector<Reading> temps;
string oname = "raw_temps.txt";
ofstream ost(oname);
int random_temperatur(int seed, int max) {
srand(seed);
return randint(max);
}
char random_suffix(int seed) {
srand(seed);
if (randint(100) <= 50) {
return ‘c’;
}
else {
return ‘f’;
}
}
void fill_vector(vector<Reading>& _temps) {
cout << "Generating Data." << endl;
int h;
double t;
char s;
int temp_hour = 0;
for (int i = 0; i < 50; i++) {
if (!(i % 24)) {
temp_hour = 0;
}
h = temp_hour;
t = random_temperatur(0, 90);
s = random_suffix(1);
_temps.push_back(Reading{ h, t, s});
temp_hour++;
}
}
void write_file(vector<Reading>& _temps) {
cout << "Writing File." << endl;
for (int i = 0; i < temps.size(); i++) {
ost << _temps[i];
}
cout << "Done!" << endl;
}
int main()
try
{
fill_vector(temps);
write_file(temps);
keep_window_open();
}
catch (runtime_error e) {
cout << e.what() << endl;
keep_window_open();
}
catch (…) {
cout << "Exiting" << endl;
keep_window_open();
}
[/code]
Output: Generating Data. Writing File. Done! Please enter a character to exit
Output-File raw_temps.txt: 0 78 c 1 1 c 2 72 c 3 65 c 4 49 f 5 48 c 6 67 f 7 20 c 8 76 f 9 36 c 10 15 c 11 16 c 12 34 c 13 37 f 14 79 f 15 60 f 16 15 c 17 1 c 18 84 c 19 79 f 20 0 c 21 86 f 22 76 c 23 73 c 0 74 f 1 22 f 2 28 f 3 30 c 4 36 c 5 0 c 6 60 f 7 78 f 8 56 c 9 51 f 10 40 f 11 52 f 12 15 f 13 47 f 14 59 f 15 82 f 16 77 c 17 46 f 18 1 c 19 0 c 20 1 c 21 2 c 22 15 c 23 36 c 0 87 c 1 29 c
