【PAT】A1088 Rational Arithmetic (20分)（分數的四則運算(全)）

1088 Rational Arithmetic (20分)

題目鏈接

#include<iostream>
#include<cmath>
using namespace std;
#include<cstdlib>

typedef long long ll;

struct Fraction{
	ll up;
	ll down;
}fraction[2];

char sign[4] = {'+', '-', '*', '/'};

ll gcd(ll a, ll b)
{
	return b==0 ? a : gcd(b, a%b);
}

//如果分母爲負數，則分子分母同時取相反數；
//如果分子爲0，則分母爲1；
//如果分子分母有公約數，則化簡 
Fraction reduction(Fraction a)
{
	if(a.down < 0){
		a.down = -a.down;
		a.up = -a.up;
	}
	else if(a.up == 0)
		a.down = 1;
	else{
		int d = gcd(abs(a.up), abs(a.down));
		a.up /= d;
		a.down /= d;
	}
	return a;
}

Fraction add(Fraction a, Fraction b)
{
	Fraction temp;
	temp.up = a.up * b.down + a.down * b.up;
	temp.down = a.down * b.down;
	return reduction(temp);
}

Fraction sub(Fraction a, Fraction b)
{
	Fraction temp;
	temp.up = a.up * b.down - a.down * b.up;
	temp.down = a.down * b.down;
	return reduction(temp);
}

Fraction multi(Fraction a, Fraction b)
{
	Fraction temp;
	temp.up = a.up * b.up;
	temp.down = a.down * b.down;
	return reduction(temp);
}

Fraction divide(Fraction a, Fraction b)
{
	Fraction temp;
	temp.up = a.up * b.down;
	temp.down = a.down * b.up;
	return reduction(temp);
}

void print(Fraction a)
{
	a = reduction(a); 
	if(a.up < 0)
		cout<<"(";
	if(a.down == 1)
		cout<<a.up;
	else if(a.up == 0)
		cout<<"0";
	else if(abs(a.up) > a.down)
		cout<<a.up/a.down<<" "<<abs(a.up) % (int)a.down<<"/"<<a.down;
	else{
		cout<<a.up<<"/"<<a.down;
	}
	if(a.up < 0)
		cout<<")";
}

int main()
{
	for(int i=0;i<2;i++)
	{
		scanf("%lld/%lld", &fraction[i].up, &fraction[i].down);
	}
	for(int i=0;i<4;i++)
	{
		print(fraction[0]);
		cout<<" "<<sign[i]<<" ";
		print(fraction[1]);
		cout<<" = ";
		switch(i){
			case 0:
				print(add(fraction[0], fraction[1]));
				break;
			case 1:
				print(sub(fraction[0], fraction[1]));
				break;
			case 2:
				print(multi(fraction[0], fraction[1]));
				break;
			case 3:
				if(fraction[1].up == 0)
					cout<<"Inf"<<endl;
				else
					print(divide(fraction[0], fraction[1]));
				break;
		}
		if(i!=3)
			cout<<endl;
	}
	return 0;
}