سورس کد تشخیص اول بودن یک عدد در C++

#include<iostream.h>
#include<math.h>
 main()
{
	 int x;

	 cin>>x;
	 int z=2;
	 for(int i=2;i<sqrt(x);i++)
		  if (x%i==0) z=z+1;
	 if (z==2 && x!=1 && x!=4) cout<<"adad aval ast"<<endl;
	 else cout<<"addade aval nist"<<endl;
}

#include <iostream>
#include <math.h>
#include <conio.h>
using namespace std;
int main()
{
    int x, a, b, c, d;
    cout<<"This program for finding number is prime or not\nPlease enter a number"<<endl;
    cin>>x;
    if (x<=3)
    {
        cout<<x<<" is prime"<<endl;
        getch();
        return(0);
    }
    a=sqrt(x);
    for (b=2;b<=a;b++)
    {
        d=x%b;
        if (d==0)
        {
            cout<<x<<"%"<<b<<"=0"<<endl;
            cout<<x<<" is not prime"<<endl;
            getch();
            return(0);
        }
    }
    cout<<x<<" is prime"<<endl;
    getch();
return(0);
}

 #include<iostream.h>
#include<conio.h>

main()
{
int number;
int counter = 0;
cout<<"enter number to progress it for prime:";
cin>>number;
for(int i=2; i <= number/2 ; i++)
{
      if(!(number%i))
      counter++;
}
if (!counter)
     cout<<"\nnumber "<<number<<" is "<<"prime";
 else
      cout<<"\nnumber "<<number<<" is Not "<<"prime";

getch();
return 0;
}