Number Is Prime Or Not

A positive integer value which is only divisible by 1 and itself is known as prime number.

#include <iostream>
using namespace std;

int main()
{
  int n, i, flag=0;
    
  cout << "Enter a positive integer value: ";
  cin >> n;
  
  for(i = 2; i <= n / 2; ++i)
  {
      if(n % i == 0)
      {
          flag = 1;
          break;
      }
  }
  
  if (flag==0)
      cout << "This is a prime number";
  else
      cout << "This is not a prime number";
	  
  return 0;
}

OutPut

Enter a positive integer value: 29
This is a prime number.