Simple find primes implementation

Question

i have idea "find primes between 1 and n". Algorithms based on residual division. i use 2 array pr and nt. [pr is saved primes. nt is saved counter number.] ex. begin with 3 3 is primes => pr0 = 3 and nt0 = 2. primes >3 is odd. when i = 5 nt0 = nt0-1 = 1 => 5 is prime. And pr1 = 5, nt1 =pr1 -1 = 4. when i = 7 : nt0 = nt0 -1 = 0, => 7 is prime. and pr2 = 7, nt2 = 6. when i = 9 nt0 < 0 => 9 is not prime. nt0 = pr0 -1 = 2, nt1 = 3, nt2 = 5. ....

    using System;
    namespace primes
    { // program for find primes between 1 and n.
    class Program
    {    public  static void Main()
        {           
            int[] pr = new int[100], ct = new int[100];             
            ct[0] = 2;
            pr[0] = 3;// 3 is primes => n[0] is 3 . 
            int n = 1; // n is number of primes.
            for (int i = 5; i < 111; i += 2)
            {               
                for (int l = 0; l < n; l++)
                { if (ct[l] >= 0)
                    {
                       ct[l]--  ;
                        //Console.Write("{0} ", ct[l]);                     
                    }                    
                  else
                    {
                        ct[l] = pr[l] - 1  ;
                     //  Console.Write("{0} ", ct[l]);
                        for (int a = l + 1; a < n; a++)
                        {
                            ct[a]--;
                         //   Console.Write("{0} ", ct[a]);
                        }
                    //    Console.WriteLine();
                        goto resume; // when ct <0 jump to resume
                    }                
                }
           //     Console.WriteLine();
                pr[n] = i;
                ct[n] = i ;                
            //    Console.Write("{0} ", ct[n]);
                n++;
            resume : ;
            }
            for (int m = 0; m < n; m++)
            {
                Console.Write(" {0}", pr[m]);
            }
            Console.ReadKey();            
        }
    }  
    }

i want to print primes 3,5,7,11, 13... but i when i run: 3 5 7 9 13 15 17 23 29 37 39 63 65 71 89. i dont understand. Can you help me?

Answer 1

我用错了

 if (ct[l] >= 0)
                    {
                       ct[l]--  ;
                        //Console.Write("{0} ", ct[l]);                     
                    }                    
                  else {
.... goto resume ;
} 

当ct [l] <0且ct [k] <0（k> l）=> ct [l] = pr [l] -1时。  但是ct [k] = ct [k] -1。“

 if(v != 0)
                { v = 0;// =>i is not prime and v = 0.
                }
               else  { 
                pr[n] = i;// =>i is prime
                ct[n] = i-1 ;          
                n++;

Answer 2

谢谢。 我完成了程序。 这是我的代码：

using System;

namespace primes
{ // program for find primes between 1 and n.
    class Program
    {    public  static void Main()
        {           
            int[] pr = new int[100], ct = new int[100];             
            ct[0] = 2;
            pr[0] = 3;// 3 is primes => n[0] is 3 . 
            int n = 1;
            int v = 0;
            for (int i = 5; i < 111; i += 2)
            {               
                for (int l = 0; l < n; l++)
                { if (ct[l] == 0)
                    {
                        ct[l] = pr[l] - 1;
                        v++;                                       
                    }
                    else
                    {
                        ct[l]--;                        
                    }                        
                }    
                if(v != 0)
                { v = 0;
                }
               else  { 
                pr[n] = i;
                ct[n] = i-1 ;          
                n++;
            }

            }
            for (int m = 0; m < n; m++)
            {
                Console.Write(" {0}", pr[m]);
            }
            Console.ReadKey();            
        }
    }  
}