範例程式碼 uva10235

//uva10235
#include<iostream>
using namespace std;

int com[1000000];
int main() {
	for(int i = 2; i < 1000; i++) {
		if(com[i])
			continue;
		for(int j = i + i; j < 1000000; j += i)
			com[j] = 1;
	}
	int n, rn;
	while(cin >> n) {
		int sn = n; 
		for(rn = 0; n; n /= 10) rn = rn * 10 + (n % 10);
		if(com[sn]) cout << sn << " is not prime.";
		else if(com[rn]) cout << sn << " is prime.";
		else if(sn == rn) cout << sn << " is prime.";
		else cout << sn << " is emirp.";
		cout << endl;
	}
	return 0;
}