UVA 10780 - Again Prime? No Time.

题目链接

思路好想，注意细节。错了很多次。

 #include <cstdio>
 #include <cstring>
 #include <string>
 #include <cmath>
 #include <ctime>
 #include <cstdlib>
 #include <iostream>
 using namespace std;
 #define MOD 1000000
 int prim[];
 int o[];
 int flag[];
 int aim[];
 int main()
 {
     int t,n,m,i,j,num = ,minz,temp,cas = ;
     for(i = ;i <= ;i ++)
     {
         if(!o[i])
         {
             prim[num++] = i;
             for(j = i+i;j <= ;j += i)
             {
                 o[j] = ;
             }
         }
     }
     scanf("%d",&t);
     while(t--)
     {
         scanf("%d%d",&m,&n);
         int tm = m;
         memset(flag,,sizeof(flag));
         memset(aim,,sizeof(aim));
         for(i = ;i <= n;i ++)
         {
             temp = i;
             for(j = ;j < num;j ++)
             {
                 if(temp == ) break;
                 while(temp%prim[j] == )
                 {
                     flag[j] ++;
                     temp /= prim[j];
                 }
             }
         }
         minz = ;
         for(j = ;j < num;j ++)
         {
             while(m%prim[j] == )
             {
                aim[j] ++;
                m /= prim[j];
             }
         }
         for(j = ;j < num;j ++)
         {
             if(tm%prim[j] == )
             minz = min(flag[j]/aim[j],minz);
         }
         if(minz == )
         printf("Case %d:\nImpossible to divide\n",cas++);
         else
         printf("Case %d:\n%d\n",cas++,minz);
     }
     return ;
 }