Question

Write a program that finds and output all of the prime numbers between 2 to 2000 to the display screen. You are to declare any required array in main and pass them to your function sieve that will process the array.C++

Answer 1

PROGRAM:

#include <iostream>
using namespace std;
int Array_prime(int a[])
{
   int i,j,index=0,c=0,num;
   for(i=2;i<=2000;i++)   
   {
       c=0;
       num=a[index]; // store array values
       for(j=1;j<=num;j++) // prime logic
       {
           if(num%j==0)
           {
               c++; // counting factor of given number
           }
       }
      
       if(c==2) // if factors euqal to 2 then it is prime
       {
           cout<< a[index] <<' ';
       }
       index++;
   }  
}
int main()
{
   int i=0,index=0;
   int a[1998]; // declaring an array that can store number between 2-2000   
   for(i=2;i<=2000;i++)
   {
       a[index]=i; // storing values to array
       index++;
   }
   Array_prime(a); //passing array to function

   return 0;
}

OUTPUT: