全 WA 求调 https://www.luogu.com.cn/record/197323143

#include <bits/stdc++.h>
using namespace std;
#define pass
#define BREAK Sleep(100)
#define WAIT Sleep(200)
#define SLEEP Sleep(500)


struct FenShu
{
	int son,mum;
	
	
	// Found
	FenShu() :
		son(0),
		mum(1)
	{
		return pass;
	}
	
	FenShu(const int _num) :
		son(_num),
		mum(1)
	{
		return pass;
	}
	
	FenShu(const double _num) :
		son((int)(_num*1e10)/__gcd((int)(_num*1e10),(int)(1e10))),
		mum((int)(1e10)/__gcd((int)(_num*1e10),(int)(1e10)))
	{
		return pass;
	}
	
	FenShu(const int _son,const int _mum) :
		son(_son),
		mum(_mum)
	{
		Error();
		return pass;
	}
	
	
	// Basic
	void Error(int err=0) const
	{
		if(err == 1 || mum == 0)
			cout << " [ERROR] 分母为零！\n",err = 1;
		else return pass;
		exit(-err);
	}
	void scan()
	{
		std::scanf("%d%d",&son,&mum);
		return pass;
	}
	void scanf()
	{
		double num;
		std::scanf("%lf",&num);
		son = (long long)(num*1e15)/__gcd((long long)(num*1e15),(long long)(1e15));
		mum = (long long)(1e15)/__gcd((long long)(num*1e15),(long long)(1e15));
		return pass;
	}
	void print() const
	{
		std::printf("%d/%d",son,mum);
		return pass;
	}
	void printf(const int BaoLiu = -1) const
	{
		if(BaoLiu == -1)
			std::cout << son*1.0/mum;
		else std::printf(("%" + to_string(BaoLiu) + "lf").c_str(),son*1.0/mum);
		return pass;
	}
	
	
	// If of Two-X
	bool operator == (const FenShu b) const
	{
		return (son * b.mum / __gcd(mum,b.mum)  ==  b.son * mum / __gcd(mum,b.mum));
	}
	bool operator <  (const FenShu b) const
	{
		return (son * b.mum / __gcd(mum,b.mum)  <   b.son * mum / __gcd(mum,b.mum));
	}
	bool operator >  (const FenShu b) const
	{
		return (son * b.mum / __gcd(mum,b.mum)  >   b.son * mum / __gcd(mum,b.mum));
	}
	bool operator <= (const FenShu b) const
	{
		return (son * b.mum / __gcd(mum,b.mum)  <=  b.son * mum / __gcd(mum,b.mum));
	}
	bool operator >= (const FenShu b) const
	{
		return (son * b.mum / __gcd(mum,b.mum)  >=  b.son * mum / __gcd(mum,b.mum));
	}
	
	
	// Operator of One-X
	FenShu YueFen() const
	{
		FenShu c;
		c.son = son / __gcd(son,mum);
		c.mum = mum / __gcd(son,mum);
		return c;
	}
	FenShu operator ~ () const
	{
		FenShu c;
		c.son = son / __gcd(son,mum);
		c.mum = mum / __gcd(son,mum);
		return c;
	}
	FenShu DaoShu() const
	{
		FenShu c;
		c.son = mum;
		c.mum = son;
		c.Error();
		return c;
	}
	FenShu operator ! () const
	{
		FenShu c;
		c.son = mum;
		c.mum = son;
		c.Error();
		return c;
	}
	
	// Operator of Two-X
	FenShu operator + (const FenShu b) const
	{
		FenShu c;
		c.son = son * b.mum / __gcd(mum,b.mum) + b.son * mum / __gcd(mum,b.mum);
		c.mum = mum * b.mum / __gcd(mum,b.mum);
		return c;
	}
	FenShu operator - (const FenShu b) const
	{
		FenShu c;
		c.son = son * b.mum / __gcd(mum,b.mum) - b.son * mum / __gcd(mum,b.mum);
		c.mum = mum * b.mum / __gcd(mum,b.mum);
		return c;
	}
	FenShu operator * (const FenShu b) const
	{
		FenShu c;
		c.son = son * b.son;
		c.mum = mum * b.mum;
		c = ~c;
		return c;
	}
	FenShu operator / (const FenShu b) const
	{
		FenShu c;
		c.son = son * b.mum;
		c.mum = mum * b.son;
		c.Error();
		c = ~c;
		return c;
	}
};
// FenShu to Else Type
double FStof(const FenShu fs)
{
	return fs.son*1.0/fs.mum;
}
int FStoi(const FenShu fs)
{
	return fs.son/fs.mum;
}
FenShu to_FS(const double num)
{
	FenShu fs(num);
	return fs;
}
FenShu to_FS(const int num)
{
	FenShu fs(num);
	return fs;
}


FenShu a,b;

int main()
{
	a.scanf(); b.scanf();
	(a - to_FS(FStoi(a/b)) * b).printf(); cout << "\n";
	
	return 0;
}