如何在c++中交替增加和减少用户输入

#include <iostream>

int main() {
    int num = 0;
    char operation;

    while (true) {
        std::cout << "当前数值：" << num << std::endl;
        std::cout << "请输入要执行的操作（+/-）：";
        std::cin >> operation;

        if (operation == '+') {
            int input;
            std::cout << "请输入要增加的值：";
            std::cin >> input;
            num += input;
        } else if (operation == '-') {
            int input;
            std::cout << "请输入要减少的值：";
            std::cin >> input;
            num -= input;
        } else {
            std::cout << "无效的操作符！" << std::endl;
            continue;
        }
    }

    return 0;
}