不好意思，修改时不小心提交了．看这个

#include <stdio.h>
void main()
{  unsigned long x,y,m,n,L;
   scanf("%ld %ld %ld %ld %ld",&x,&y,&m,&n,&L);
   if (m==n) 
	printf("Impossible\n");
   else
   	{ 
        if(m>n)
        	{m=m-n;
		x=(y-x+L)%L;
		}
        else 
		{m=n-m;
		x=(x-y+L)%L;
		}   
        n=x/m;
	x=x%m;
	y=x;                       
        while(1)
        	{if(y==0) 
			{printf("%ld\n",n);
			break;
			}  
          	n=n+(y+L)/m;y=(y+L)%m;                           
          	if(y==x) 
			{printf("Impossible\n");
			break;
			}  
        	}                                                            
   	}
}

• Re:不好意思． (716) 20082741 2009-12-14 19:23:15