Data update

Task/Convert-decimal-number-to-rational/C++/convert-decimal-number-to-rational.cpp

@@ -0,0 +1,75 @@
+#include <cmath>
+#include <cstdint>
+#include <iostream>
+#include <limits>
+#include <numeric>
+#include <vector>
+
+class Rational {
+public:
+	Rational(const int64_t& numer, const uint64_t& denom) : numerator(numer), denominator(denom) { }
+
+	Rational negate() {
+		return Rational(-numerator, denominator);
+	}
+
+	std::string to_string() {
+		return std::to_string(numerator) + " / " + std::to_string(denominator);
+	}
+
+private:
+	int64_t numerator;
+	uint64_t denominator;
+};
+/**
+ * Return a Rational such that its numerator / denominator = 'decimal', correct to dp decimal places,
+ * where dp is minimum of 'decimal_places' and the number of decimal places in 'decimal'.
+ */
+Rational decimal_to_rational(double decimal, const uint32_t& decimal_places) {
+	const double epsilon = 1.0 / std::pow(10, decimal_places);
+
+	const bool negative = ( decimal < 0.0 );
+	if ( negative ) {
+		decimal = -decimal;
+	}
+
+	if ( decimal < std::numeric_limits<double>::min() ) {
+		return Rational(0, 1);
+	}
+
+	if ( std::abs( decimal - std::round(decimal) ) < epsilon )  {
+		return Rational(std::round(decimal), 1);
+	}
+
+	uint64_t a = 0;
+	uint64_t b = 1;
+	uint64_t c = static_cast<uint64_t>(std::ceil(decimal));
+	uint64_t d = 1;
+	const uint64_t auxiliary_1 = std::numeric_limits<uint64_t>::max() / 2;
+
+	while ( c < auxiliary_1 && d < auxiliary_1 ) {
+		const double auxiliary_2 = static_cast<double>( a + c ) / ( b + d );
+
+		if ( std::abs(decimal - auxiliary_2) < epsilon ) {
+			break;
+		}
+
+		if ( decimal > auxiliary_2 ) {
+			a = a + c;
+			b = b + d;
+		} else {
+			c = a + c;
+			d = b + d;
+		}
+	}
+
+	const uint64_t divisor = std::gcd(( a + c ), ( b + d ));
+	Rational result(( a + c ) / divisor, ( b + d ) / divisor);
+	return ( negative ) ? result.negate() : result;
+}
+
+int main() {
+	for ( const double& decimal : { 3.1415926535, 0.518518, -0.75, 0.518518518518, -0.9054054054054, -0.0, 2.0 } ) {
+		std::cout << decimal_to_rational(decimal, 9).to_string() << std::endl;
+	}
+}

Task/Convert-decimal-number-to-rational/Frink/convert-decimal-number-to-rational.frink

@@ -0,0 +1,3 @@
+println[toRational[0.9054054]]
+println[toRational[0.518518]]
+println[toRational[0.75]]

Task/Convert-decimal-number-to-rational/Seed7/convert-decimal-number-to-rational.seed7

@@ -3,6 +3,22 @@ $ include "seed7_05.s7i";
 
 const proc: main is func
   begin
+    writeln(bigRational parse "0.9(054)");
+    writeln(bigRational parse "0.(518)");
+    writeln(bigRational parse "0.75");
+    writeln(bigRational parse "3.(142857)");
+    writeln(bigRational parse "0.(8867924528301)");
+    writeln(bigRational parse "0.(846153)");
+    writeln(bigRational parse "0.9054054");
+    writeln(bigRational parse "0.518518");
+    writeln(bigRational parse "0.14285714285714");
+    writeln(bigRational parse "3.14159265358979");
+    writeln(bigRational parse "2.718281828");
+    writeln(bigRational parse "31.415926536");
+    writeln(bigRational parse "0.000000000");
+
+    writeln;
+
     writeln(fraction(bigRational("0.9(054)")));
     writeln(fraction(bigRational("0.(518)")));
     writeln(fraction(bigRational("0.75")));