#pragma once
template <typename T>
class MyStack {
	struct Node {
		T elem;
		Node* next;

		Node(T elem, Node* next = nullptr): elem(elem), next(next){}
	};

	Node* myTop;

public:
	MyStack():myTop(nullptr){}
	~MyStack() {
		while (!is_empty()) pop();
	}

	bool is_empty() {
		return myTop == nullptr;
	}

	bool push(T elem) {
		myTop = new Node(elem, myTop);
		return true;
	}

	bool pop() {
		if (!is_empty()) {
			Node* aux = myTop;
			myTop = myTop->next;
			delete aux;
			return true;
		}
		return false;
	}

	T top() { return myTop->elem; }

};






#pragma once

class Stacks {
	float* elems;
	unsigned int numElems;
	unsigned int cap;

public:
	Stacks(int cap) : cap(cap), numElems(0), elems (new float[cap]){}
	~Stacks() {
		delete[]elems;
	}

	bool is_empty() {
		return numElems == 0;
	}

	bool is_full() {
		return numElems == cap;
	}

	bool push(float elem) {
		if (!is_full()) {
			elems[numElems++] = elem;
		}
		else {
			return false;
		}
	}

	bool pop() {
		if (!is_empty()) {
			--numElems;
			return true;
		}
		else { return false;
		}
	}

	float top() {
		return elems[numElems - 1];
	}

};






#include <iostream>
#include <string>
#include <sstream>
#include "MyStack.h"
using namespace std;

int main() {
	string expr, elem;
	MyStack <float> pilin;

	for (;;) {
		cout << "Expresion: "; getline(cin, expr);
		if (expr == "exit") break;

		istringstream iss(expr);
		while (iss >> elem) {
			if ((elem[0] >= '0' && elem[0] <= '9') || (elem[0] == '-' && elem.size() > 1)) {
				float operand = stof(elem);
				cout << "Operando a pila: " << operand << endl;
				pilin.push(operand);
			}
			else {
				float b = pilin.top(); pilin.pop();
				float a = pilin.top(); pilin.pop();
				float result;
				switch (elem[0]) {
				case '-': result = a - b;
					cout << "Resultado: " << result << endl;
					break;
				case '+': result = a + b;
					cout << "Resultado: " << result << endl;
					break;
				case '*': result = a * b;
					cout << "Resultado: " << result << endl;
					break;
				case '/': result = a / b;
					cout << "Resultado: " << result << endl;
					break;
				}
				cout << "Operador: " << elem << endl;
			}
		}
	}




	return 0;
}