findthenextprime.cpp

#include <iostream>
#include <math.h>
using namespace std;
// declare functions
int prime(int n);

int main() {
	int n1;
	int i;
	
	cout << "enter a number to test for first prime above ";
	cin >> n1;
	
		
	for (i=n1; ?; i++) {
		if (prime(i)){
			cout << i << " is prime" << endl;
			break;
		}
	}
	return 0;
}

int prime(int n) {
	int i;
	int sn;
	
	sn = sqrt((double)n);
	for(i=2; i<=sn; i++) {
		if(n%i==0)
			return false;
	}
	return true;
}