[C++] 삼성 5658. [모의 SW 역량테스트] 보물상자 비밀번호

#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
 
using namespace std;
 
int arr[28];
vector<int> input;
 
void rotate_square(int line_num, int count) {
    if (count != 0) {
        int tmp1 = arr[0];
        int tmp2;
        for (int i = 0; i < (line_num * 4) - 1; i++) {
            tmp2 = arr[i + 1];
            arr[i + 1] = tmp1;
            tmp1 = tmp2;
        }
        arr[0] = tmp2;
    }
 
    for (int i = 0; i < 4; i++) {
        int number = 0;
        int mul = 1;
        for (int j = line_num - 1; j >= 0; j--) {
            number += arr[line_num * i + j] * mul;
            mul *= 16;
        }
        input.push_back(number);
    }
}
 
int main() {
    int T;
    cin >> T;
    for (int t = 1; t <= T; t++) {
        int N, K;
        string nums;
        cin >> N >> K;
        cin.ignore();
        getline(cin, nums);
 
        for (int n = 0; n < N; n++) {
            if (nums[n] >= '0'&& nums[n] <= '9')
                arr[n] = nums[n] - '0';
            else if (nums[n] >= 'A' && nums[n] <= 'F')
                arr[n] = nums[n] - 'A' + 0xa;
        }
 
        for (int i = 0; i < N/4; i++) {
            rotate_square(N/4, i);
        }
        
        sort(input.begin(), input.end(), greater<int>());
        input.erase(unique(input.begin(), input.end()), input.end());
        
        cout << "#" << t << " " << input[K - 1] << endl;
        input.clear();
    }
    return 0;
}