[9480/ C++] 민정이와 광직이의 알파벳 공부

#include <iostream>
#define endl '\n'
#define MAXN 16
using namespace std;

int arr[MAXN];
int n, cnt;
int cmp = (1 << 26) - 1; // 0b11111111111111111111111111

void dfs(int idx, int cur){
    if(n == idx) {
        if(cur == cmp) cnt++;
        return;
    }
    dfs(idx + 1, cur | arr[idx]);
    dfs(idx + 1, cur);
}

int main(){
    cin.tie(nullptr) -> sync_with_stdio(false);
    int T;
    cin >> T;
    
    for(int tc = 1; tc <= T; ++tc){
        cin >> n;
        cnt = 0;
        for(int i = 0; i < n; i++){
            int val = 0;
            
            string str;
            cin >> str;
            
            for(int j = 0; j < str.size(); j++){
                val |= 1 << (str[j] - 'a');
            }
            arr[i] = val;
        }
        dfs(0, 0);
        cout << '#' << tc << ' ' << cnt << endl;
    }
}