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eatmelon说:
用LISP写一个程序，他可以读取输入字符串中的算式，并计算它们
的值。
(defun solve-eq (eq) (if (listp eq) ; if eq is a list, evaluate it (eval eq) (if (stringp eq) ; if eq is a string, convert it to a list (eval (read-from-string eq)) (format t "Error: Invalid input~%") ; otherwise, report an error ))) (defun start () (loop (format t "Enter equation: ") ; prompt user for equation (let ((eq (read-line))) ; read input as string (if (eq eq "quit") ; if user enters "quit" (return) ; then exit the loop (format t "Answer: ~a~%" (solve-eq eq)))))) ; otherwise, solve the equation (start) -
eatmelon说:
用C++写一个函数，他能够读取一个XML文档，并解析这个XML文档，将其中标签为AA的标签的内容输出，只允许使用标准库
和C++11特性
#include #include #include #include #include void ReadXMLFile(const std::string& file_path) { std::ifstream file(file_path); std::string line; std::string tag = "AA"; while (std::getline(file, line)) { //使用正则表达式匹配要输出的内容 std::regex pattern(R"((.*?))"); std::smatch result; if (std::regex_search(line, result, pattern)) { std::cout << "标签AA的内容是: " << result.str(1) << std::endl; } } }
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