#include<iostream.h>
#include<conio.h>
main()
{
int n,i,f=1;
cout<<"enter any no to check prime";
cin>>n;
for(i=2;i<n;i++)
{
  if(n%i==0)
  k=2;
}
if(k==2)
cout<<"the no is not prime"<<endl;
else
cout<<"the no is prime";
}
getch();
}

/*To check whethere Entered no. is PRIME or NOT*/
  #include<iostream.h>
  #include<conio.h>
  main()
  {
		int num,i;
		clrscr();
		cout<<"Enter the any no.="<<"\n";
		cin>>num;
		for(i=2;i<=num;i++)
		{
			if(num%i==0)
			{
				break;
			}
		}
		if(i==num)
		{
			cout<<"The number entered is a 
PRIME no.";
		}
		else
		{
			cout<<"The number entered is NOT a 
PRIME no.";
		}
		getch();
  }

#include<stdio.h>
#include<conio.h>
main()
{
int n,s=0,i;
clrscr();
printf("Enter the number\n");
scanf("%d",&n);
for(i=2;i<n/2;i++)
{
if(n%i==0)
 s++;
}
     if(s>=1)
     printf("%d is not prime",n);
     else
     printf("%d is prime",n);
     getch();
}
ill execute it .it's cent percent correct.

#include <iostream>
using namespace std;

void main()
{
	int num;
	int flag = 0;
	cout<<"enter a number"<<endl;
	cin>>num;
	for(int i=2;i<num;i++)
		{
			if((num%i) == 0)
			{
				flag = 1;
				break;
			}
		}
		if (flag == 1)
				cout<<"Not Prime"<<endl;
		else
				cout<<"Prime"<<endl;
			 
}