feat(09): finishing the exercice 01

cpp09/ex01/main.cpp

@@ -1,24 +1,16 @@
-/* ************************************************************************** */
-/*                                                                            */
-/*                                                        :::      ::::::::   */
-/*   main.cpp                                           :+:      :+:    :+:   */
-/*                                                    +:+ +:+         +:+     */
-/*   By: rparodi <rparodi@student.42.fr>            +#+  +:+       +#+        */
-/*                                                +#+#+#+#+#+   +#+           */
-/*   Created: 2025/04/27 12:58:08 by rparodi           #+#    #+#             */
-/*   Updated: 2025/04/27 15:50:20 by rparodi          ###   ########.fr       */
-/*                                                                            */
-/* ************************************************************************** */
-
-#include <iostream>
-#include <stack>
 #include "RPN.hpp"
+#include <algorithm>
+#include <iostream>
+#include <iterator>
+#include <sstream>
+#include <list>
+#include <string>
 
 /**
- * @brief check if the input have only numbers and operators
+ * @brief Check if the input string is valid
  *
- * @param str the input of the user
- * @return true if the input is valid, false otherwise
+ * @param str input of the user
+ * @return true if the input is valid
  */
 bool check_input(std::string str) {
 	std::string allowed = "0123456789 +-*/";
@@ -29,12 +21,117 @@ bool check_input(std::string str) {
 	return true;
 }
 
+/**
+ * @brief split the input string into a list of tokens
+ *
+ * @param input input of the user (already checked)
+ * @return std::list<tok> list of tokens
+ */
+std::list<tok> split_to_list(const std::string& input) {
+	std::istringstream iss(input);
+	std::string token;
+	std::list<tok> tokens;
+	e_op op;
+	int tmp;
+
+	while (iss >> token) {
+		op = NUM;
+		tmp = 0;
+		if (token == "*") {
+			op = MUL;
+		}
+		else if (token == "/") {
+			op = DIV;
+		}
+		else if (token == "+") {
+			op = ADD;
+		}
+		else if (token == "-") {
+			op = SUB;
+		}
+		else {
+			op = NUM;
+			tmp = std::strtol(token.c_str(), 0, 10);
+		}
+		tok to_push = {op, tmp};
+		tokens.push_back(to_push);
+	}
+	return tokens;
+}
+
+/**
+ * @brief Execute the RPN algorithm
+ *
+ * @param tokens list of tokens
+ * @return true if the execution was successful
+ */
+bool exec_rpn(std::list<tok> tokens) {
+	if (tokens.size() < 3) {
+		std::cerr << CLR_RED << "Error:\tNot enough operands" << CLR_RESET << std::endl;
+		return false;
+	}
+
+	std::list<int> numbers;
+
+	while (!tokens.empty()) {
+		tok current = tokens.front();
+		tokens.pop_front();
+
+		if (current.type == NUM) {
+			numbers.push_back(current.value);
+		}
+		else if (current.type == ADD || current.type == SUB || current.type == MUL || current.type == DIV) {
+			if (numbers.size() < 2) {
+				std::cerr << CLR_RED << "Error:\tNot enough operands for operator" << CLR_RESET << std::endl;
+				return false;
+			}
+
+			int b = numbers.back();
+			numbers.pop_back();
+			int a = numbers.back();
+			numbers.pop_back();
+
+			if (current.type == ADD)
+				numbers.push_back(a + b);
+			else if (current.type == SUB)
+				numbers.push_back(a - b);
+			else if (current.type == MUL)
+				numbers.push_back(a * b);
+			else if (current.type == DIV) {
+				if (b == 0) {
+					std::cerr << CLR_RED << "Error:\tDivision by zero" << CLR_RESET << std::endl;
+					return false;
+				}
+				numbers.push_back(a / b);
+			}
+		}
+		else {
+			std::cerr << CLR_RED << "Error:\tInvalid token" << CLR_RESET << std::endl;
+			return false;
+		}
+	}
+
+	if (numbers.size() != 1) {
+		std::cerr << CLR_RED << "Error:\tInvalid final stack state" << CLR_RESET << std::endl;
+		return false;
+	}
+
+	std::cout << CLR_GREEN << "Result:\t" << numbers.back() << CLR_RESET << std::endl;
+	return true;
+}
+
 int main(int argc, char **argv) {
 	if (argc != 2) {
 		std::cerr << CLR_RED << "Usage:\t" << argv[0] << " <string>" << CLR_RESET << std::endl;
+		return 1;
 	}
 	std::string input = argv[1];
 	if (!check_input(input)) {
 		std::cerr << CLR_RED << "Error:\tYour input can only have digits, spaces and the operators '+' '-' '*' '/'" << CLR_RESET << std::endl;
+		return 1;
+	} else {
+		std::list<tok> tokens = split_to_list(input);
+		exec_rpn(tokens);
 	}
 }
+