Stack.cpp

//  
//  algorithm - some algorithms in "Introduction to Algorithms", third edition
//  Copyright (C) 2018  lxylxy123456
//  
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Affero General Public License as
//  published by the Free Software Foundation, either version 3 of the
//  License, or (at your option) any later version.
//  
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Affero General Public License for more details.
//  
//  You should have received a copy of the GNU Affero General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
//  

#ifndef MAIN
#define MAIN
#define MAIN_Stack
#endif

#ifndef FUNC_Stack
#define FUNC_Stack

#include <exception>
#include "utils.h"

template <typename T>
class Stack {
	public:
		Stack(size_t size): top(0), data(new T[size]) {}
		bool StackEmpty() { return top == 0; }
		void Push(T x) { data[top++] = x; }
		T Pop() {
			if (StackEmpty())
				throw std::invalid_argument("underflow"); 
			else
				return data[--top]; 
		}
		void MultiPop(size_t k) {
			while (!StackEmpty() && k--)
				Pop(); 
		}
		~Stack() { delete [] data; }
	private:
		size_t top; 
		T* data; 
}; 
#endif

#ifdef MAIN_Stack
int main(int argc, char *argv[]) {
	const size_t n = get_argv(argc, argv, 1, 16); 
	Stack<int> S(n); 
	std::cout << "e / E: test empty" << std::endl; 
	std::cout << "p / u: push" << std::endl; 
	std::cout << "P / o: pop" << std::endl; 
	std::cout << "m / M: multi pop" << std::endl; 
	std::cout << "q / Q: quit" << std::endl; 
	while (true) {
		char c; int x; 
		std::cout << ">> "; 
		if (!(std::cin >> c)) {
			std::cout << std::endl; 
			break; 
		}
		switch (c) {
			case 'e': 
			case 'E': 
				std::cout << std::boolalpha << S.StackEmpty() << std::endl; 
				break; 
			case 'p': 
			case 'u': 
				std::cout << "x = "; 
				std::cin >> x; 
				S.Push(x); 
				break; 
			case 'P': 
			case 'o': 
				std::cout << S.Pop() << std::endl; 
				break; 
			case 'm': 
			case 'M': 
				std::cout << "k = "; 
				std::cin >> x; 
				S.MultiPop(x); 
				break; 
			case 'q': 
			case 'Q': 
				return 0; 
		}
	}
	return 0; 
}
#endif