求助！

请大佬帮忙改一下代码 题目：请编写一段有关计算器的代码要求：实现最基础的加减乘除运算，并能在各种进制间转换，并能计算日期的c++代码

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

// 执行基本运算
double calc(double num1, char op, double num2) {
    switch (op) {
        case '+':
            return num1 + num2;
        case '-':
            return num1 - num2;
        case '*':
            return num1 * num2;
        case '/':
            if (num2 == 0) {
                cerr << "错误：除数不能为零！" << endl;
                return 0;
            }
            return num1 / num2;
        default:
            cerr << "错误：无效的运算符！" << endl;
            return 0;
    }
}

// 十进制转其他进制
string decToOtherBase(int decimal, int targetBase) {
    if (decimal == 0) return "0";
    string result = "";
    while (decimal > 0) {
        int rem = decimal % targetBase;
        result = (rem < 10? to_string(rem) : static_cast<char>(rem - 10 + 'A')) + result;
        decimal /= targetBase;
    }
    return result;
}

// 其他进制转十进制
int otherBaseToDec(string number, int sourceBase) {
    int result = 0;
    int power = 1;
    for (int i = number.length() - 1; i >= 0; --i) {
        int digit = (number[i] >= '0' && number[i] <= '9')? number[i] - '0' : number[i] - 'A' + 10;
        result += digit * power;
        power *= sourceBase;
    }
    return result;
}

// 计算日期
void calcDate(int days) {
    time_t curTime = time(nullptr);
    tm* curDate = localtime(&curTime);
    curDate->tm_mday += days;
    time_t newTime = mktime(curDate);
    char buffer[80];
    strftime(buffer, sizeof(buffer), "%Y-%m-%d", curDate);
    cout << "增加 " << days << " 天后的日期：" << buffer << endl;
}

int main() {
    // 基本运算示例
    double num1, num2;
    char op;
    cout << "请输入第一个数、运算符、第二个数（例如：2 + 3）：";
    cin >> num1 >> op >> num2;
    double result = calc(num1, op, num2);
    cout << "结果：" << result << endl;

    // 进制转换示例
    int decimalNum;
    int targetBase;
    cout << "请输入要转换的十进制数：";
    cin >> decimalNum;
    cout << "请输入要转换到的进制（2 - 16）：";
    cin >> targetBase;
    string converted = decToOtherBase(decimalNum, targetBase);
    cout << decimalNum << " 转成 " << targetBase << " 进制为：" << converted << endl;

    string numberInBase;
    int sourceBase;
    cout << "请输入一个指定进制（2 - 16）下的数来转换为十进制：";
    cin >> numberInBase;
    cout << "请输入该数的进制：";
    cin >> sourceBase;
    int decimalResult = otherBaseToDec(numberInBase, sourceBase);
    cout << numberInBase << " 在 " << sourceBase << " 进制下转成十进制为：" << decimalResult << endl;

    // 日期计算示例
    int days;
    cout << "请输入要在当前日期上增加的天数：";
    cin >> days;
    calcDate(days);

    return 0;
}

谢谢啦！！