题解 | ranko的手表

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

const int MAX_HOUR = 23;
const int MAX_MINUTE = 59;

// 验证时间是否有效
bool isValidTime(const string& time) {
    if (time.size() != 4) return false;
    
    int hour = stoi(time.substr(0, 2));
    int minute = stoi(time.substr(2, 2));
    
    return hour >= 0 && hour <= MAX_HOUR && minute >= 0 && minute <= MAX_MINUTE;
}

// 比较两个时间，返回true如果time1 < time2
bool isEarlier(const string& time1, const string& time2) {
    return time1 < time2;  // 字符串比较可以直接比较时间
}

// 计算时间差（分钟）
int timeDiff(const string& s1, const string& s2) {
    int h1 = stoi(s1.substr(0, 2));
    int m1 = stoi(s1.substr(2, 2));
    int h2 = stoi(s2.substr(0, 2));
    int m2 = stoi(s2.substr(2, 2));
    
    return (h2 - h1) * 60 + (m2 - m1);
}

// 生成所有可能的时间组合
void generateTimes(const string& pattern, vector<string>& result, int index = 0, string current = "") {
    if (index == 4) {
        if (isValidTime(current)) {
            result.push_back(current);
        }
        return;
    }
    
    if (pattern[index] == '?') {
        for (char c = '0'; c <= '9'; c++) {
            generateTimes(pattern, result, index + 1, current + c);
        }
    } else {
        generateTimes(pattern, result, index + 1, current + pattern[index]);
    }
}

int main() {
    string t1, t2;
    getline(cin, t1);
    getline(cin, t2);
    
    // 移除冒号
    t1.erase(remove(t1.begin(), t1.end(), ':'), t1.end());
    t2.erase(remove(t2.begin(), t2.end(), ':'), t2.end());
    
    // 生成所有可能的时间组合
    vector<string> times1, times2;
    generateTimes(t1, times1);
    generateTimes(t2, times2);
    
    if (times1.empty() || times2.empty()) {
        cout << "Invalid time format" << endl;
        return 0;
    }
    
    // 计算满足s1 < s2的最小和最大时间差
    int min_diff = INT_MAX;
    int max_diff = INT_MIN;
    bool found = false;
    
    for (const auto& time1 : times1) {
        for (const auto& time2 : times2) {
            if (isEarlier(time1, time2)) {
                int diff = timeDiff(time1, time2);
                min_diff = min(min_diff, diff);
                max_diff = max(max_diff, diff);
                found = true;
            }
        }
    }
    
    if (!found) {
      // cout << "No valid time pairs found (s1 must be earlier than s2)" << endl;
    } else {
        cout << min_diff << " " << max_diff << endl;
    }
    
    return 0;
}

去：，转换？生成字符串，遍历计算结果