#include<iostream.h> 

int simplify(int s,int t)	//寻找 s 和 t 的最大公约数，并返回最大公约数
{
	int a, b, r;

	if ( t > s)
	{ 
		a = t ; b = s ;
	}
	
    else
	{ 
		a = s ; b = t ; 
	}

	r = b ;	
	
	while ( r != 0 )
	{ 
		r = a % b ;		
		a = b ;			
		b = r ;
	}
	
	return a;
}

int result(int a,int b,int c)
{
	int r;

	r = simplify(a,c);

	if(r!=1 && b%r!=0)
		return 0;
	
	else 
		return 1;
}


int main()
{
	unsigned long A,B;
	unsigned long x,y,m,n,l;
	cin>>x>>y>>m>>n>>l;//(x!=y)
	if(x==y)
		return 0;
	if(x>=2000000000)
		return 0;
	if(y>=2000000000)
		return 0;
	if(m<=0||m>=2000000000)
		return 0;
	if(n<=0||n>=2000000000)
		return 0;
	if(l<=0||l>=2100000000)
		return 0;
	int a = m-n;
	if(a==0)
	{	cout<<"impossible"<<endl;  }
	else
	{
		if(a>0)
		{
			A = x;
			B = y;
			a = a;
		}
		else
		{
			A = y;
			B = x;
			a = -a;							// 12 10 3 7 22
		}

		if(result(a,(A-B),l)==0)  //确认是否可以到达
			cout<<"impossible"<<endl;	

		else
		{
			for(int i=0;;i++)
			{
				A += a;
				if((A-B)%l==0)
					break;
			}
			cout<<i+1<<endl;
		}
	}
	return 0;
}

• 老师WA关你什么事，你不WA不就行了？^_^ (1319) liulibo133 2007-12-05 00:08:53
  • Re:老师WA关你什么事，你不WA不就行了？^_^ (10) minstar 2007-12-05 11:53:28