From 72612a10079e68e96ddaeffaa9d5dbb8ed6d2090 Mon Sep 17 00:00:00 2001
From: "Luna Mira Lage (Desoroxxx)" <desoroxxx.git@redstudio.dev>
Date: Wed, 23 Sep 2026 18:02:52 +0200
Subject: [PATCH] ex01

Signed-off-by: Luna Mira Lage (Desoroxxx) <desoroxxx.git@redstudio.dev>
---
 ex01/Makefile     |  4 +++
 ex01/src/RPN.cpp  | 85 +++++++++++++++++++++++++++++++++++++++++++++++
 ex01/src/RPN.hpp  | 15 +++++++++
 ex01/src/main.cpp | 20 +++++++++++
 4 files changed, 124 insertions(+)
 create mode 100644 ex01/Makefile
 create mode 100644 ex01/src/RPN.cpp
 create mode 100644 ex01/src/RPN.hpp
 create mode 100644 ex01/src/main.cpp

diff --git a/ex01/Makefile b/ex01/Makefile
new file mode 100644
index 0000000..e99f4bf
--- /dev/null
+++ b/ex01/Makefile
@@ -0,0 +1,4 @@
+override NAME = RPN
+override SRC_FILES = main.cpp RPN.cpp
+
+include ../Makefile
diff --git a/ex01/src/RPN.cpp b/ex01/src/RPN.cpp
new file mode 100644
index 0000000..9ab2a54
--- /dev/null
+++ b/ex01/src/RPN.cpp
@@ -0,0 +1,85 @@
+#include <RPN.hpp>
+
+#include <cctype>
+#include <stack>
+#include <stdexcept>
+
+RPN::RPN() {}
+
+RPN::RPN(const RPN& other) { (void)other; }
+
+enum Operator { PLUS, MINUS, MULTIPLY, DIVIDE };
+
+static bool isOperator(char c) { return c == '+' || c == '-' || c == '*' || c == '/'; }
+
+static Operator getOperator(char c) {
+	switch (c) {
+	case '+':
+		return PLUS;
+	case '-':
+		return MINUS;
+	case '*':
+		return MULTIPLY;
+	case '/':
+		return DIVIDE;
+	default:
+		throw std::runtime_error("");
+	}
+}
+
+static long operate(const Operator& op, const long& a, const long& b) {
+	switch (op) {
+	case PLUS:
+		return a + b;
+	case MINUS:
+		return a - b;
+	case MULTIPLY:
+		return a * b;
+	case DIVIDE:
+		return a / b;
+	}
+}
+
+long RPN::evaluate(const std::string& expression) const {
+	std::stack<long> stack;
+
+	for (size_t i = 0; i < expression.size(); ++i) {
+		if (expression[i] == ' ')
+			continue;
+
+		if (isOperator(expression[i])) {
+			if (stack.size() < 2)
+				throw std::runtime_error("");
+
+			const Operator op = getOperator(expression[i]);
+
+			const long b = stack.top();
+			stack.pop();
+			const long a = stack.top();
+			stack.pop();
+
+			if (op == DIVIDE && b == 0)
+				throw std::runtime_error("");
+
+			stack.push(operate(op, a, b));
+		} else if (std::isdigit(static_cast<unsigned char>(expression[i]))) {
+			stack.push(expression[i] - '0');
+		} else {
+			throw std::runtime_error("");
+		}
+	}
+
+	if (stack.size() != 1)
+		throw std::runtime_error("");
+
+	return stack.top();
+}
+
+RPN& RPN::operator=(const RPN& other) {
+	if (this == &other)
+		return *this;
+
+	return *this;
+}
+
+RPN::~RPN() {}
diff --git a/ex01/src/RPN.hpp b/ex01/src/RPN.hpp
new file mode 100644
index 0000000..f92dba0
--- /dev/null
+++ b/ex01/src/RPN.hpp
@@ -0,0 +1,15 @@
+#pragma once
+
+#include <string>
+
+class RPN {
+  public:
+	RPN();
+	RPN(const RPN& other);
+
+	long evaluate(const std::string& expression) const;
+
+	RPN& operator=(const RPN& other);
+
+	~RPN();
+};
diff --git a/ex01/src/main.cpp b/ex01/src/main.cpp
new file mode 100644
index 0000000..74512a4
--- /dev/null
+++ b/ex01/src/main.cpp
@@ -0,0 +1,20 @@
+#include <RPN.hpp>
+#include <cstdlib>
+#include <iostream>
+
+int main(int argc, char* argv[]) {
+	if (argc != 2) {
+		std::cerr << "Usage: " << argv[0] << " <expression>" << std::endl;
+		return 1;
+	}
+
+	try {
+		const RPN rpn;
+
+		std::cout << rpn.evaluate(argv[1]) << std::endl;
+	} catch (const std::exception& exception) {
+		std::cerr << "Error" << std::endl;
+		std::cerr << exception.what() << std::endl;
+		return EXIT_FAILURE;
+	}
+}
-- 
2.51.2