C++の授業：「区間」クラスのオペレーター

0517

#include <iostream>
#include <cstdlib>

using namespace std;

	//アクセサを定義しないIntervalクラス
class Interval
{
private:
  double upperLimit;
  double lowerLimit;

public:
  Interval(double u, double l)
  {
    upperLimit = u;
    lowerLimit = l;
  }
  friend Interval operator+(Interval a, Interval b);
  friend Interval operator*(Interval a, Interval b);
  friend ostream &operator<<(ostream &stream, Interval interval);
};

//区間同士の和
Interval operator+(Interval a, Interval b)
{
  Interval sum = Interval(a.upperLimit + b.upperLimit, a.lowerLimit + b.lowerLimit);
  return sum;
}

//区間同士の積
Interval operator*(Interval a, Interval b)
{
  Interval product = Interval(a.upperLimit * b.upperLimit, a.lowerLimit * b.lowerLimit);
  return product;
}

//整数*区間
Interval operator*(double d, Interval interval)
{
  return Interval(d, d) * interval;
}
//区間*整数(今回は不必要)
Interval operator*(Interval interval, double d)
{
  return d * interval;
}

//区間の入力
istream &operator>>(istream &stream, Interval &interval)
{
  double upL, lowL;
  stream >> upL >> lowL;
  interval = Interval(upL, lowL);
  return stream;
}

//区間の出力
ostream &operator<<(ostream &stream, Interval interval)
{
  stream << "[" + interval.upperLimit + ", " + interval.lowerLimit + "]";
  return stream;
}

int main(){
	Interval a,b;
	cout << "";
	cin >> a;
	cout << "";
	cin >> b;
	cout << "a+b=" << a+b << endl;
	cout << "a*b=" << a*b << endl;
	cout << "b+2a=" << b+2*a << endl;
	return 0;
}

Interval.cpp

#include <istream>
using namespace std;
class Interval
{
private:
  int upperLimit;
  int lowerLimit;

public:
  Interval(int u, int l)
  {
    upperLimit = u;
    lowerLimit = l;
  }
  int getUpperLimit() { return upperLimit; }
  int getLowerLimit() { return lowerLimit; }
};

//区間同士の和
Interval operator+(Interval a, Interval b)
{
  Interval sum = Interval(a.getUpperLimit() + b.getUpperLimit(), a.getLowerLimit() + b.getLowerLimit());
  return sum;
}

//区間同士の積
Interval operator*(Interval a, Interval b)
{
  Interval product = Interval(a.getUpperLimit() * b.getUpperLimit(), a.getLowerLimit() * b.getLowerLimit());
  return product;
}

//整数*区間
Interval operator*(int integer, Interval interval)
{
  return Interval(integer, integer) * interval;
}
//区間*整数(今回は不必要)
Interval operator*(Interval interval, int integer)
{
  return integer * interval;
}

//区間の入力
istream &operator>>(istream &stream, Interval &interval)
{
  int upL, lowL;
  stream >> upL >> lowL;
  interval = Interval(upL, lowL);
  return stream;
}

//区間の出力
ostream &operator<<(ostream &stream, Interval interval)
{
  stream << "[" + interval.getUpperLimit() + ", " + interval.getLowerLimit() + "]";
  return stream;
}