🐣 문제

링크 : https://school.programmers.co.kr/learn/courses/30/lessons/42839

🐥 코드

#include <string>
#include <vector>
#include <algorithm>

using namespace std;

bool isPrime(int n){
    if (n < 2) return false;
    for(int i = 2; i*i <= n; i++){
        if(n % i == 0) return false;
    }
    return true;
}

int solution(string numbers) {
    int answer = 0;
    
    vector<int> v;
    
    for(int i = 0; i < numbers.size(); i++){
        v.push_back(numbers[i] - '0');
    }
    
    sort(v.begin(),v.end());
    vector<int> ans;
    
    do{
        for(int i = 0; i <= v.size(); i++){
            int tmp = 0;
            for(int j = 0; j < i; j++){
                tmp = (tmp * 10) + v[j];
                ans.push_back(tmp);
            }
        }   
    } while(next_permutation(v.begin(), v.end()));
    
    sort(ans.begin(), ans.end());
    ans.erase(unique(ans.begin(), ans.end()), ans.end());
    
    for(int i = 0; i < ans.size(); i++){
        if(isPrime(ans[i])) answer += 1;
    }
        
    return answer;
}