Date(const Date d) { _year = d._year; _month = d._month; _day = d._day;}无限递归调用的原因

这段代码中的问题在于函数的参数是按值传递的，也就是说在函数调用时会创建参数的一个副本，而这个副本的初始化需要调用拷贝构造函数，而函数的参数又是一个对象，因此会不断递归调用拷贝构造函数，导致无限递归调用。

可以修改代码来避免这个问题，可以将函数的参数改为按引用传递，即将参数声明为 "const Date& d"，这样在函数调用时不会创建副本，也不会无限递归调用拷贝构造函数。

相关问题

class Date { public: Date(int year = 1900, int month = 1, int day = 1) { _year = year; _month = month; _day = day; } //bool opeartor==(Date* this, const Date& d2) //左操作数是this，指向调用函数的对象 bool operator==(const Date& d2) { return _year == d2._year && _month == d2._month && _day == d2._day; } private: int _year; int _month; int _day; }; int main() { Date d1(2023, 7, 13); Date d2(2023, 7, 12); cout << (d1 == d2) << endl; operator==(d1, d2); //cout << (operator==(d1, d2)) << endl; cout << d1.operator==(d2) << endl; return 0; }错误原因

错误原因是在调用 `operator==` 函数时的语法错误。

在 `main` 函数中，`operator==(d1, d2);` 这行代码是错误的。应该使用 `d1.operator==(d2);` 来调用成员函数 `operator==`。

另外，注释掉的 `cout` 语句 `//cout << (operator==(d1, d2)) << endl;` 也是错误的，因为 `operator==` 不是一个全局函数，不能直接通过函数名调用。

正确的调用方式是使用成员函数的形式，如 `cout << d1.operator==(d2) << endl;`。这样会调用 `d1` 对象的 `operator==` 成员函数，并输出结果。

#include <iostream> #include <cstdio> #include <cstring> using namespace std; const char* Haab_month_name[] = {"pop", "no", "zip", "zotz", "tzec", "xul", "yoxkin", "mol", "chen", "yax", "zac", "ceh", "mac", "kankin", "muan", "pax", "koyab", "cumhu", "uayet"}; int Tzolkin_day_number[20] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 1, 2, 3, 4, 5, 6, 7}; const char *Tzolkin_day_name[] = {"imix", "ik", "akbal", "kan", "chicchan", "cimi", "manik", "lamat", "muluk", "ok", "chuen", "eb", "ben", "ix", "mem", "cib", "caban", "eznab", "canac", "ahau"}; struct Date { int day; int month; int year; }; // 把哈布历转换成天数 int haab_to_days(int day, const char* month, int year) { int total_days = day + (year * 365); int month_index; for (month_index = 0; month_index < 19; ++month_index) { if (strcmp(Haab_month_name[month_index], month) == 0) { break; } } total_days += month_index * 20; return total_days; } // 把天数转换成托尔金历 void days_to_tzolkin(int total_days, int* day_number, const char** day_name) { int tzolkin_day_count = total_days % 13; int tzolkin_day_index = tzolkin_day_count - 1; if (tzolkin_day_index < 0) tzolkin_day_index = 12; int tzolkin_day_number = Tzolkin_day_number[tzolkin_day_index]; const char *tzolkin_day_name = Tzolkin_day_name[(total_days % 20)]; *day_number = tzolkin_day_number; *day_name = tzolkin_day_name; } int main() { int N; cin >> N; cout << N << endl; for (int i = 0; i < N; ++i) { Date date; char dot; scanf("%d%c%d%s%d", &date.day, &dot, &date.month, Haab_month_name, &date.year); int total_days = haab_to_days(date.day, Haab_month_name, date.year); int tzolkin_day_number; const char *tzolkin_day_name; days_to_tzolkin(total_days, &tzolkin_day_number, &tzolkin_day_name); printf("%d %s %d\n", tzolkin_day_number, tzolkin_day_name, date.year); } return 0; }

这是一个使用 C++ 编写的程序，用于将 Maya 文化中的哈布历转换为托尔金历。程序主要包括以下几个部分：

1. 头文件和命名空间声明

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

2. 定义哈布月份和托尔金日期的名称和数字

const char* Haab_month_name[] = {"pop", "no", "zip", "zotz", "tzec",
                                "xul", "yoxkin", "mol", "chen", "yax",
                                "zac", "ceh", "mac", "kankin", "muan",
                                "pax", "koyab", "cumhu", "uayet"};
int Tzolkin_day_number[20] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
                              11, 12, 13, 1, 2, 3, 4, 5, 6, 7};
const char *Tzolkin_day_name[] = {"imix", "ik", "akbal", "kan", "chicchan",
                                  "cimi", "manik", "lamat", "muluk", "ok",
                                  "chuen", "eb", "ben", "ix", "mem", "cib",
                                  "caban", "eznab", "canac", "ahau"};

3. 定义一个日期结构体

struct Date {
    int day;
    int month;
    int year;
};

4. 把哈布历转换成天数

int haab_to_days(int day, const char* month, int year) {
    int total_days = day + (year * 365);
    int month_index;
    for (month_index = 0; month_index < 19; ++month_index) {
        if (strcmp(Haab_month_name[month_index], month) == 0) {
            break;
        }
    }
    total_days += month_index * 20;
    return total_days;
}

5. 把天数转换成托尔金历

void days_to_tzolkin(int total_days, int* day_number, const char** day_name) {
    int tzolkin_day_count = total_days % 13;
    int tzolkin_day_index = tzolkin_day_count - 1;
    if (tzolkin_day_index < 0)
        tzolkin_day_index = 12;
    int tzolkin_day_number = Tzolkin_day_number[tzolkin_day_index];
    const char *tzolkin_day_name = Tzolkin_day_name[(total_days % 20)];
    *day_number = tzolkin_day_number;
    *day_name = tzolkin_day_name;
}

6. 主函数，用于读取输入、调用转换函数、并输出结果

int main() {
    int N;
    cin >> N;
    cout << N << endl;

    for (int i = 0; i < N; ++i) {
        Date date;
        char dot;
        scanf("%d%c%d%s%d", &date.day, &dot, &date.month,
               Haab_month_name, &date.year);

        int total_days = haab_to_days(date.day, Haab_month_name, date.year);
        int tzolkin_day_number;
        const char *tzolkin_day_name;
        days_to_tzolkin(total_days, &tzolkin_day_number, &tzolkin_day_name);

        printf("%d %s %d\n", tzolkin_day_number,
               tzolkin_day_name, date.year);
    }

    return 0;
}

以上就是这个程序的主要内容和流程。