RosettaCodeData/Task/Imaginary-base-numbers/C++/imaginary-base-numbers.cpp

146 lines
4.1 KiB
C++

#include <algorithm>
#include <complex>
#include <iomanip>
#include <iostream>
std::complex<double> inv(const std::complex<double>& c) {
double denom = c.real() * c.real() + c.imag() * c.imag();
return std::complex<double>(c.real() / denom, -c.imag() / denom);
}
class QuaterImaginary {
public:
QuaterImaginary(const std::string& s) : b2i(s) {
static std::string base("0123.");
if (b2i.empty()
|| std::any_of(s.cbegin(), s.cend(), [](char c) { return base.find(c) == std::string::npos; })
|| std::count(s.cbegin(), s.cend(), '.') > 1) {
throw std::runtime_error("Invalid base 2i number");
}
}
QuaterImaginary& operator=(const QuaterImaginary& q) {
b2i = q.b2i;
return *this;
}
std::complex<double> toComplex() const {
int pointPos = b2i.find('.');
int posLen = (pointPos != std::string::npos) ? pointPos : b2i.length();
std::complex<double> sum(0.0, 0.0);
std::complex<double> prod(1.0, 0.0);
for (int j = 0; j < posLen; j++) {
double k = (b2i[posLen - 1 - j] - '0');
if (k > 0.0) {
sum += prod * k;
}
prod *= twoI;
}
if (pointPos != -1) {
prod = invTwoI;
for (size_t j = posLen + 1; j < b2i.length(); j++) {
double k = (b2i[j] - '0');
if (k > 0.0) {
sum += prod * k;
}
prod *= invTwoI;
}
}
return sum;
}
friend std::ostream& operator<<(std::ostream&, const QuaterImaginary&);
private:
const std::complex<double> twoI{ 0.0, 2.0 };
const std::complex<double> invTwoI = inv(twoI);
std::string b2i;
};
std::ostream& operator<<(std::ostream& os, const QuaterImaginary& q) {
return os << q.b2i;
}
// only works properly if 'real' and 'imag' are both integral
QuaterImaginary toQuaterImaginary(const std::complex<double>& c) {
if (c.real() == 0.0 && c.imag() == 0.0) return QuaterImaginary("0");
int re = (int)c.real();
int im = (int)c.imag();
int fi = -1;
std::stringstream ss;
while (re != 0) {
int rem = re % -4;
re /= -4;
if (rem < 0) {
rem = 4 + rem;
re++;
}
ss << rem << 0;
}
if (im != 0) {
double f = (std::complex<double>(0.0, c.imag()) / std::complex<double>(0.0, 2.0)).real();
im = (int)ceil(f);
f = -4.0 * (f - im);
size_t index = 1;
while (im != 0) {
int rem = im % -4;
im /= -4;
if (rem < 0) {
rem = 4 + rem;
im++;
}
if (index < ss.str().length()) {
ss.str()[index] = (char)(rem + 48);
} else {
ss << 0 << rem;
}
index += 2;
}
fi = (int)f;
}
auto r = ss.str();
std::reverse(r.begin(), r.end());
ss.str("");
ss.clear();
ss << r;
if (fi != -1) ss << '.' << fi;
r = ss.str();
r.erase(r.begin(), std::find_if(r.begin(), r.end(), [](char c) { return c != '0'; }));
if (r[0] == '.')r = "0" + r;
return QuaterImaginary(r);
}
int main() {
using namespace std;
for (int i = 1; i <= 16; i++) {
complex<double> c1(i, 0);
QuaterImaginary qi = toQuaterImaginary(c1);
complex<double> c2 = qi.toComplex();
cout << setw(8) << c1 << " -> " << setw(8) << qi << " -> " << setw(8) << c2 << " ";
c1 = -c1;
qi = toQuaterImaginary(c1);
c2 = qi.toComplex();
cout << setw(8) << c1 << " -> " << setw(8) << qi << " -> " << setw(8) << c2 << endl;
}
cout << endl;
for (int i = 1; i <= 16; i++) {
complex<double> c1(0, i);
QuaterImaginary qi = toQuaterImaginary(c1);
complex<double> c2 = qi.toComplex();
cout << setw(8) << c1 << " -> " << setw(8) << qi << " -> " << setw(8) << c2 << " ";
c1 = -c1;
qi = toQuaterImaginary(c1);
c2 = qi.toComplex();
cout << setw(8) << c1 << " -> " << setw(8) << qi << " -> " << setw(8) << c2 << endl;
}
return 0;
}