74 lines
2.2 KiB
C++
74 lines
2.2 KiB
C++
#include "GeneralUtility.h"
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#include <string>
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#include <sstream>
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#include <stdexcept>
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// Fast 64-bit int power function
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std::uint64_t Powuli(const std::uint64_t& b, const std::uint64_t& e) {
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std::uint64_t buf = 1;
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for (std::uint64_t i = 0; i < e; i++)
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buf *= b;
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return buf;
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}
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std::uint64_t GeneralUtility::BaseX_2_10(const std::string& num, const std::string& set) {
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unsigned long long int buf = 0;
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for (std::size_t i = 0; i < num.length(); i++) {
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for (std::size_t j = 0; j < set.length(); j++) {
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if (num[i] == set[j]) {
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buf += Powuli((std::uint64_t)set.length(), (uint64_t)(num.length() - (i + 1))) * j;
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break;
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}
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}
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}
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return buf;
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}
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// Based on: https://www.geeksforgeeks.org/divide-large-number-represented-string/
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std::pair<std::string, int>
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GeneralUtility::StringDivision(const std::string& dividend, const unsigned int divisor, const std::string& set) {
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// No set? Throw logic error
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if (set.length() == 0)
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throw std::logic_error("Can't divide a number of base0! Please supple a nonempty set!");
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// No division by 0
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if (divisor == 0)
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throw std::overflow_error("Division by zero!");
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// As result can be very large store it in string
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std::stringstream ss;
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// Find prefix of number that is larger than divisor.
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int idx = 0;
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int temp = Ord(dividend[idx], set);
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while (temp < divisor)
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temp = temp * set.length() + Ord(dividend[++idx], set);
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// Repeatedly divide divisor with temp. After
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// every division, update temp to include one
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// more digit.
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int curRest = temp % divisor;
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while (dividend.size() > idx) {
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// Store result in answer i.e. temp / divisor
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ss << (char)(set[(temp / divisor)]);
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curRest = temp % divisor;
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// Take next digit of number
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temp = (temp % divisor) * set.length() + Ord(dividend[++idx], set);
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}
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// If divisor is greater than number
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if (ss.str().length() == 0)
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{
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// Generate 0-value string
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std::stringstream ss;
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ss << set[0];
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return std::make_pair(ss.str(), BaseX_2_10(dividend, set));
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}
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// else return the answer
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return std::make_pair(ss.str(), curRest);
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}
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