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// multi_input.cpp : Defines the entry point for the console application.
// Osman Zakir
// 3 / 4 / 2017
// Bjarne Stroustrup: Programming: Principles and Practice Using C++ 2nd Edition
// Chapter 11 Exercise 4
// Exercise Specifications:
/**
* Write a program called multi_input.cpp that prompts the user to enter
* several integers in any combination of octal, decimal, or hexadecimal,
* using the 0 and 0x base suffixes; interprets the numbers correctly; and
* converts them to decimal form. Then your program should output the
* values in properly spaced columns like this:
* 0x43 hexadecimal converts to 67 decimal
* 0123 octal converts to 83 decimal
* 65 decimal converts to 65 decimal
*/
#include "../../cust_std_lib_facilities.h"
#include <iostream>
#include <locale>
#include <string>
#include <iomanip>
#include <sstream>
#include <stdexcept>
#include <vector>
int base_of(std::string &num_s);
std::vector<std::string> split(const std::string &line);
void print_results(const int base, const int number, const std::string num_s);
int main()
{
using namespace std;
cout << "Please enter some numbers in any combination of decimal, hexadecimal, "
<< "or octal.\nUse the '0x' and '0' suffixes "
<< "for hexadecimal and octal as needed.\n";
string input;
getline(cin, input);
for (string num_s : split(input))
{
try
{
const int base = base_of(num_s);
size_t position;
int number = stoi(num_s, addressof(position), base);
print_results(base, number, num_s);
}
catch (const invalid_argument &inv_arg)
{
cerr << "invalid argument error: " << inv_arg.what() << '\n';
}
catch (const out_of_range &oor)
{
cerr << "out of range error: " << oor.what() << '\n';
}
}
keep_window_open();
}
int base_of(std::string &num_s)
{
using namespace std;
if (num_s.find_first_of("+-") == 0)
{
num_s = num_s.substr(1);
}
if (num_s.empty() || !isdigit(num_s.front()))
{
throw invalid_argument("");
}
if (num_s.front() == '0')
{
if (num_s.size() > 1 && tolower(num_s[1]) == 'x')
{
return 16;
}
else
{
return 8;
}
}
return 10;
}
std::vector<std::string> split(const std::string &line)
{
using namespace std;
vector<string> result;
istringstream ist{ line };
string str;
while (ist >> str)
{
result.push_back(str);
}
return result;
}
void print_results(const int base, const int number, const std::string num_s)
{
using namespace std;
switch (base)
{
case 8:
cout << right << setw(5) << num_s << right << setw(8) << " octal "
<< setw(19) << right << " converts to "
<< right << setw(4) << number << " decimal\n";
break;
case 10:
cout << right << setw(5) << num_s << right << setw(10) << " decimal "
<< setw(17) << right << " converts to "
<< right << setw(4) << number << " decimal\n";
break;
case 16:
cout << right << setw(5) << num_s << right << setw(14) << " hexadecimal "
<< setw(11) << right << " converts to "
<< right << setw(4) << number << " decimal\n";
break;
}
}
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