public List<Integer> combination(int num) {
List<Integer> primes = new ArrayList<Integer>();
for (int i = 2; num > 1; i++) {
for (; num % i == 0; num /= i) {
primes.add(i);
}
}
return primes;
}
List<Integer> primes = new ArrayList<Integer>();
for (int i = 2; num > 1; i++) {
for (; num % i == 0; num /= i) {
primes.add(i);
}
}
return primes;
}