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Primesums.cpp
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Primesums.cpp
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#include <math.h>
#include <iostream>
using namespace std;
bool isPrime(unsigned long input);
int main() {
unsigned long input, sumDigits;
while (true) {
cin >> input;
if (input == 0)
return 0;
sumDigits = 0;
for (int i = 1; input >= pow(10,i-1); i++) {
sumDigits += input % (int)(pow(10, i)) / (int)(pow(10, i - 1));
}
if (isPrime(sumDigits)) {
if (isPrime(input))
cout << input << " is a double primesum\n";
else
cout << input << " is a primesum\n";
}
else
cout << input << " is neither\n";
}
return 0;
}
bool isPrime(unsigned long input) {
if (input == 1)
return false;
for (unsigned long i = 2; i <= sqrt(input); i++) {
if (input % i == 0)
return false;
}
return true;
}