1868875_wa.c

北大大牛代码 1240道题的原代码 超级权威

# include <stdio.h>

int main()
{
 long m, n, r, l, i;
 
 while(scanf("%ld%ld",&m,&n)==2)
 {
  if(n==0) {printf("1\n");continue;}
   n = m-n+1;
   r=(m-n+1)/10*10;
   m-=r;
   l = 1;
   switch((r/10)%4)
   {
    case 1: l = 8;break;
    case 2: l = 4;break;
    case 3: l = 2;break;
    case 0: if(r) l = 6;break;
   }
   for(i = n; i <= m; i++)
    {
     if(i%10==1||i%10==0) continue;
     l*=(i%10);
     while(l%10==0)
     {
      l/=10;
     }
     l%=10;
     if(!l) l=1;
    }
    if(!l) l=1;
    printf("%ld\n",l);
 }
}