题解 | 牛牛的考试

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

char compare_func(const vector<string>& arr) {

    vector<int> lengths;
    for (const auto& c : arr) {
        lengths.push_back(c.size());
    }

    // auto it = lengths.begin();
    // auto min_it = it;
    // for (; it != lengths.end(); ++it) {
    //     if (*it < *min_it) min_it = it;
    // }
    // int min_len = *min_it;
    int min_len = *min_element(lengths.begin(), lengths.end()); // STL algorithm
    int max_len = *max_element(lengths.begin(), lengths.end());

    int min_count = count(lengths.begin(), lengths.end(), min_len);
    int max_count = count(lengths.begin(), lengths.end(), max_len);

    if (min_count == 1) {
        for (int i = 0; i < 4; ++i) {
            if (lengths[i] == min_len) {
                return arr[i][0]; // Return the option prefix letter directly
            }
        }
    }

    if (max_count == 1) {
        for (int i = 0; i < 4; ++i) {
            if (lengths[i] == max_len) {
                return arr[i][0]; // Return the option prefix letter directly
            }
        }
    }

    return 'C';
}

int main() {
    int T;
    cin >> T;

    for (int i = 0; i < T; ++i) {
        vector<string> arr(4);
        for (int j = 0; j < 4; ++j) {
            cin >> arr[j];
        }
        char res = compare_func(arr);
        cout << res << endl;
    }

    return 0;
}