Hdu4002 Find the maximum Euler function

Hdu4002 Find the maximum Euler function
// Obtain N smaller than n and n/phi (x). If there are multiple N, the output is the smallest.
// Phi (x) = x * (1-1/p1) * (1-1/p2) * (1-1/p3 )....
// To maximize x/phi (x), even if (1-1/p1) * (1-1/p2) * (1-1/p3 ).... minimum
// P1, p2, p3 ,....
// All are prime factor, so we can enumerate the product of all prime factor,
// After the table is typed, find the number less than or equal to n.
# Include
# Include
# Include
Using namespace std;
Const int maxn = 1010;
Char str [maxn];
Int num [maxn] [maxn];
Int num_1 [maxn];
Int len [maxn];
Int isp [maxn];
Int prime [maxn];
Int set ()
{
Memset (isp, 0, sizeof (isp ));
Isp [1] = 1;
For (int I = 4; I <maxn; I + = 2)
Isp [I] = 1;
For (int I = 3; I <maxn; I ++)
{
If (isp [I]) continue;
For (int j = I * I; j <maxn; j + = I)
Isp [j] = 1;
}
Int j = 0;
For (int I = 1; I <maxn; I ++)
If (! Isp [I]) prime [++ j] = I;
Return j;
}
Bool cmp (int len_1, int len_2, int pos)
{
If (len_1> len_2) return 0;
If (len_2> len_1) return 1;
For (int I = len_1; I> 0; I --)
{
If (num_1 [I]> num [pos] [I])
Return 0;
If (num_1 [I] <num [pos] [I])
Return 1;
}
Return 0;
}
Void init ()
{
Int sum = set ();
Num [0] [1] = 1;
Len [0] = 1;
For (int I = 1; I ++)
{
Int c = 0;
Len [I] = len [I-1];
For (int j = 1; j <= len [I]; j ++)
{
Num [I] [j] = prime [I] * num [I-1] [j];
Num [I] [j] + = c;
C = num [I] [j]/10;
Num [I] [j] % = 10;
}
While (c)
{
Num [I] [++ len [I] = c % 10;
C/= 10;
}
If (len [I]> 100) break;
}
}
Int main ()
{
Init ();
Int T;
Scanf ("% d", & T );
While (T --)
{
Scanf ("% s", str );
Int len_1 = strlen (str );
For (int I = len_1-1; I> = 0; I --)
Num_1 [len_1-I] = str [I]-'0 ';
Int pos = 1;
While (! Cmp (len_1, len [pos], pos) pos ++;
For (int I = len [pos-1]; I> = 1; I --)
Printf ("% d", num [pos-1] [I]);
Puts ("");
}
}