박은빈

HashSet<Integer> numberSet = new HashSet<>(); public int solution(String numbers) { int answer = 0; recursive("",numbers); Iterator<Integer> it = numberSet.iterator(); while(it.hasNext()) { int number = it.next(); if(isPrime(number)) answer++; } return answer; } public void recursive(String comb, String others) { if (!comb.equals("")) numberSet.add(Integer.valueOf(comb)); for (int i = 0; i < others.length(); i++) { recursive(comb + others.charAt(i), others.substring(0, i) + others.substring(i + 1)); } } public boolean isPrime(int num) { if(num == 0 || num == 1) return false; for(int i=2; i<=(int)Math.sqrt(num); i++) { if(num%i == 0 ) return false; } return true; }