112 lines
3.4 KiB
C++
112 lines
3.4 KiB
C++
#include "GeneralUtility.h"
|
|
#include <string>
|
|
#include <sstream>
|
|
#include <stdexcept>
|
|
|
|
// Based on: https://www.geeksforgeeks.org/divide-large-number-represented-string/
|
|
std::pair<std::string, int>
|
|
GeneralUtility::StringDivision(const std::string& dividend, const unsigned int divisor, const std::string& set) {
|
|
// No set? Throw logic error
|
|
if (set.length() == 0)
|
|
throw std::logic_error("Can't divide a number of base0! Please supply a nonempty set!");
|
|
// No division by 0
|
|
if (divisor == 0)
|
|
throw std::overflow_error("Division by zero!");
|
|
|
|
// As result can be very large store it in string
|
|
std::stringstream ss;
|
|
|
|
// Find prefix of number that is larger than divisor.
|
|
int idx = 0;
|
|
int temp = Ord(dividend[idx], set);
|
|
while (temp < divisor)
|
|
temp = temp * set.length() + Ord(dividend[++idx], set);
|
|
|
|
// Repeatedly divide divisor with temp. After
|
|
// every division, update temp to include one
|
|
// more digit.
|
|
int curRest = temp % divisor;
|
|
while (dividend.size() > idx) {
|
|
// Store result in answer i.e. temp / divisor
|
|
ss << (char)(set[(temp / divisor)]);
|
|
curRest = temp % divisor;
|
|
|
|
// Take next digit of number
|
|
temp = (temp % divisor) * set.length() + Ord(dividend[++idx], set);
|
|
}
|
|
|
|
// If divisor is greater than number
|
|
if (ss.str().length() == 0)
|
|
{
|
|
// Generate 0-value string
|
|
std::stringstream ss;
|
|
ss << set[0];
|
|
return std::make_pair(ss.str(), BaseX_2_10(dividend, set));
|
|
}
|
|
|
|
// else return the answer
|
|
return std::make_pair(ss.str(), curRest);
|
|
}
|
|
|
|
std::string GeneralUtility::BaseX_2_Y(const std::string &num, const std::string &set_in, const std::string &set_out, const std::uint32_t minOutLen) {
|
|
if ((set_in.length() == 0) || (set_out.length() == 0))
|
|
throw std::logic_error("Can't convert from or to base0! Please supply a nonempty set!");
|
|
|
|
std::stringstream ss;
|
|
|
|
// Generate a 0-value string for inbase
|
|
ss << set_in[0];
|
|
const std::string zeroInbase = ss.str();
|
|
ss.str("");
|
|
|
|
|
|
if (num != zeroInbase) {
|
|
|
|
std::string buf = num;
|
|
while (buf != zeroInbase) {
|
|
const auto divRes = StringDivision(buf, set_out.length(), set_in);
|
|
const std::uint64_t mod = divRes.second;
|
|
buf = divRes.first;
|
|
ss << set_out[mod];
|
|
}
|
|
|
|
// Now reverse buf
|
|
buf = ss.str();
|
|
ss.str("");
|
|
for (std::size_t i = 0; i < buf.length(); i++)
|
|
ss << buf[buf.length() - i - 1];
|
|
}
|
|
else
|
|
{
|
|
// If num is 0, just pass a null-value. The algorithm would hang otherwise.
|
|
ss << set_out[0];
|
|
}
|
|
|
|
|
|
// Add as much null-values to the left as requested.
|
|
if (ss.str().length() < minOutLen)
|
|
{
|
|
const std::size_t cachedLen = ss.str().length();
|
|
const std::string cachedStr = ss.str();
|
|
ss.str("");
|
|
for (std::size_t i = 0; i < minOutLen - cachedLen; i++)
|
|
ss << set_out[0];
|
|
ss << cachedStr;
|
|
}
|
|
|
|
return ss.str();
|
|
}
|
|
|
|
std::string GeneralUtility::Base10_2_X(const std::uint64_t &num, const std::string &set, const std::uint32_t minOutLen) {
|
|
// Convert num to a string
|
|
std::stringstream ss;
|
|
ss << num;
|
|
const std::string numStr = ss.str();
|
|
|
|
// Use BaseX_2_Y to convert to outbase
|
|
const std::string convertedNum = BaseX_2_Y(numStr, "0123456789", set, minOutLen);
|
|
|
|
// return it
|
|
return convertedNum;
|
|
}
|