Dirichlet's Theorem on Arithmetic Progressions--POJ 3006

1、题目类型：数论。

2、解题思路：水题。

3、实现方法:

  
    

   
     
   
     #include
   
     <
   
     iostream
   
     >
   
     

   
     using
   
      
   
     namespace
   
      std;

   
     #define
   
      Max 1000010
   
     


   
     bool
   
      prime[Max],flag;

   
     int
   
      map[
   
     220
   
     ],cnt;


   
     void
   
      BuildTable()
{
 
   
     int
   
      i,j;
 prime[
   
     1
   
     ]
   
     =
   
     false
   
     ;
 prime[
   
     2
   
     ]
   
     =
   
     prime[
   
     3
   
     ]
   
     =
   
     true
   
     ;
 
   
     for
   
     (i
   
     =
   
     2
   
     ;i
   
     <
   
     1001
   
     ;i
   
     ++
   
     )
 {
 
   
     for
   
     (j
   
     =
   
     2
   
     ;j
   
     *
   
     i
   
     <
   
     Max;j
   
     ++
   
     )
 {
 prime[i
   
     *
   
     j]
   
     =
   
     false
   
     ;
 }
 }
}

   
     int
   
      main()
{
 
   
     int
   
      a,d,n,tmp;
 memset(prime,
   
     1
   
     ,
   
     sizeof
   
     (prime));
 BuildTable();
 
   
     while
   
     (cin
   
     >>
   
     a
   
     >>
   
     d
   
     >>
   
     n 
   
     &&
   
      (a
   
     ||
   
     d
   
     ||
   
     n))
 {
 cnt
   
     =
   
     0
   
     ;
 tmp
   
     =
   
     a;
 
   
     while
   
     (cnt
   
     !=
   
     n)
 {
 
   
     if
   
     (prime[tmp])
 map[
   
     ++
   
     cnt]
   
     =
   
     tmp;
 tmp
   
     +=
   
     d;
 }
 cout
   
     <<
   
     map[n]
   
     <<
   
     endl;
 }
 
   
     return
   
      
   
     1
   
     ;
}