题解：P14497 [NCPC 2025] Crochet Competition

#include<bits/stdc++.h>
using namespace std;

// 将星期缩写转换为数字(0-6)
int get_weekday(const string& w) {
    static unordered_map<string, int> weekday_map = {
        {"Mon", 0}, {"Tue", 1}, {"Wed", 2}, {"Thu", 3},
        {"Fri", 4}, {"Sat", 5}, {"Sun", 6}
    };
    return weekday_map[w];
}

// 将时间转换为总分钟数(从周一00:00开始计算)
int time_to_minutes(const string& weekday, int hour, int minute) {
    int wd = get_weekday(weekday);
    return wd * 24 * 60 + hour * 60 + minute;
}

// 解析时间字符串
void parse_time(const string& s, string& weekday, int& hour, int& minute) {
    weekday = s.substr(0, 3);
    hour = stoi(s.substr(4, 2));
    minute = stoi(s.substr(7, 2));
}

int main() {
    string start_str, end_str;
    getline(cin, start_str);
    getline(cin, end_str);
    
    string start_weekday, end_weekday;
    int start_hour, start_minute, end_hour, end_minute;
    
    parse_time(start_str, start_weekday, start_hour, start_minute);
    parse_time(end_str, end_weekday, end_hour, end_minute);
    
    int start_total = time_to_minutes(start_weekday, start_hour, start_minute);
    int end_total = time_to_minutes(end_weekday, end_hour, end_minute);
    
    const int week_minutes = 7 * 24 * 60; // 一周的总分钟数
    int diff = end_total - start_total;
    
    // 处理跨周的情况
    if (diff <= 0) {
        diff += week_minutes;
    }
    
    // 计算天、小时、分钟
    int days = diff / (24 * 60);
    diff %= (24 * 60);
    int hours = diff / 60;
    int minutes = diff % 60;
    
    // 收集非零部分
    vector<pair<int, string>> parts;
    if (days > 0) {
        parts.emplace_back(days, days == 1 ? "day" : "days");
    }
    if (hours > 0) {
        parts.emplace_back(hours, hours == 1 ? "hour" : "hours");
    }
    if (minutes > 0) {
        parts.emplace_back(minutes, minutes == 1 ? "minute" : "minutes");
    }
    
    // 输出结果
    if (parts.empty()) {
        // 这种情况只有当diff为0时才会发生，根据题目要求输出一周
        cout << "7 days" << endl;
    } else if (parts.size() == 1) {
        cout << parts[0].first << " " << parts[0].second << endl;
    } else if (parts.size() == 2) {
        cout << parts[0].first << " " << parts[0].second << " and " 
             << parts[1].first << " " << parts[1].second << endl;
    } else { // parts.size() == 3
        cout << parts[0].first << " " << parts[0].second << ", "
             << parts[1].first << " " << parts[1].second << ", "
             << parts[2].first << " " << parts[2].second << endl;
    }
    
    return 0;
}