CF 256D. Good Sequences(DP)

题目链接

主要是标记前面素数的最大的DP值，要认真一些。没想到居然写了一个很难发现的错误。

 #include <cstdio>
 #include <cstring>
 #include <string>
 #include <cmath>
 #include <ctime>
 #include <cstdlib>
 #include <iostream>
 using namespace std;
 int o[];
 int prim[];
 int p[];
 int sp[];
 int flag[];
 int main()
 {
     int i,j,n,num = ;
     int temp,maxz;
     for(i = ; i <= ; i ++)
     {
         if(!o[i])
         {
             sp[i] = num;
             for(j = i+i; j <= ; j += i)
                 o[j] = ;
             prim[num++] = i;
         }
     }
     scanf("%d",&n);
     for(i = ; i < n; i ++)
         scanf("%d",&p[i]);
     if(n == )
     {
         printf("1\n");
         return ;
     }
     for(i = ; i < n; i ++)
     {
         maxz = ;
         temp = p[i];
         for(j = ; j < ; j ++)
         {
             if(temp == ) break;
             if(temp%prim[j] == )
             {
                 maxz = max(maxz,flag[j]);
                 while(temp%prim[j] == )
                 {
                     temp /= prim[j];
                 }
             }
         }
         if(temp != )
         maxz = max(maxz,flag[sp[temp]]);
         temp = p[i];
         for(j = ; j < ; j ++)
         {
             if(temp == ) break;
             if(temp%prim[j] == )
             {
                 flag[j] = maxz + ;
                 while(temp%prim[j] == )
                 {
                     temp /= prim[j];
                 }
             }
         }
         if(temp != )
         flag[sp[temp]] = maxz + ;
     }
     maxz = ;
     for(i = ;i < num;i ++)
     {
         maxz = max(maxz,flag[i]);
     }
     printf("%d\n",maxz);
     return ;
 }