Euler 41 in C++ Using Permutation

euler41-P.cpp

#include <iostream>
#include <algorithm>
#include <sstream>
#include <cmath>

// Euler 41 in C++ Using Permutation - Solution by Raven G. Duran

// Common good ol' prime checker
bool is_prime(long int n){
	int i;
	if(n%2==0) return false;
	int sRoot = sqrt((double)n);
	for(i = 3; i <= sRoot; i+=2){
		if(n%i==0) return false;
	}
	return true;
}

int main(){
  int digits[] = {7,6,5,4,3,2,1};
  long int n;

  do {
  	std::stringstream s;
  	s << digits[0] << digits[1] << digits[2] << digits[3] << digits[4] << digits[5] << digits[6];
  	s >> n;
  	
  	if (is_prime(n)){
  		std::cout << "The Highest Pandigital Prime Number is: " << n << std::endl;
  		break;
  	}
 } while ( std::prev_permutation(digits,digits+7) );
	
  return 0;
}