#include #include #include #include #include // 添加日期库 #include struct Purchase { std::string date; std::string product; double price; }; bool compareDates(const Purchase& p1,...-Go服务器开发

你可以使用 std::get_time 替代 strptime 来解决找不到标识符的问题。下面是修正后的代码：

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <chrono>  // 添加日期库
#include <ctime>
#include <iomanip>

struct Purchase {
    std::string date;
    std::string product;
    double price;
};

bool compareDates(const Purchase& p1, const Purchase& p2) {
    // 使用日期库计算日期差值
    std::tm t1 = {}, t2 = {};
    std::istringstream iss1(p1.date), iss2(p2.date);
    
    iss1 >> std::get_time(&t1, "%Y-%m-%d");
    iss2 >> std::get_time(&t2, "%Y-%m-%d");

    auto timePoint1 = std::chrono::system_clock::from_time_t(std::mktime(&t1));
    auto timePoint2 = std::chrono::system_clock::from_time_t(std::mktime(&t2));

    return timePoint1 > timePoint2;  // 比较时间点远近，时间点越大表示时间越早
}

double calculateAveragePrice(const std::vector<Purchase>& purchases, const std::string& product, int N) {
    double sum = 0.0;
    int count = 0;

    for (const Purchase& purchase : purchases) {
        if (purchase.product == product) {
            sum += purchase.price;
            count++;
            if (count == N) break;  // 达到最近N次购买数量后退出循环
        }
    }

    return (count > 0) ? sum / count : 0.0;  // 避免除以零的情况
}

int main() {
    int m, n;
    std::cin >> m >> n;

    std::vector<Purchase> purchases(m);
    for (int i = 0; i < m; i++) {
        std::cin >> purchases[i].date >> purchases[i].product >> purchases[i].price;
    }

    std::sort(purchases.begin(), purchases.end(), compareDates);  // 按照日期远近排序

    double keyboardAvgPrice = calculateAveragePrice(purchases, "keyboard", n);
    double mouseAvgPrice = calculateAveragePrice(purchases, "mouse", n);

    std::cout << std::fixed;
    std::cout.precision(1);
    std::cout << keyboardAvgPrice << std::endl;
    std::cout << mouseAvgPrice << std::endl;

    return 0;
}

这样，你应该能够成功编译并运行代码了。

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