2022-10-24 *배열로 스택클래스 구현하기

[StackTest.java]

import java.util.Scanner;

class MyStack {
	private int[] mystack;
	private int size;// 스택의 사이즈
	private int top;

	public MyStack(int length) {
		// this.size = size;
		mystack = new int[length];
	}
	public void push(int data) {
		mystack[size] = data;
		size++;
	}
	public int empty() {
		int result = 0;
		if (size == 0) {
			result = 1;
		}
		return result;
	}
	public int pop() {
		if (empty() == 1) {
			return -1;
		} else {
			size = size - 1;
			return mystack[size];
		}
	}
	public int size() {
		return this.size;
	}

	public int top() {
		if (size == 0) {
			return -1;
		} else {
			return mystack[size - 1];
		}
	}
}

public class StackTest {

	public static void main(String[] args) throws Exception {
		// BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		Scanner key = new Scanner(System.in);
		//String str = br.readLine();
		int count = key.nextInt();
		key.nextLine();
		MyStack obj = new MyStack(count);
		for (int i = 0; i < count; i++) {
			String line = key.nextLine();
			String[] resultarr = line.split(" ");

			switch (resultarr[0]) {
			case "push":
				int data = Integer.parseInt(resultarr[1]);
				obj.push(data);
				break;
			case "top":
				System.out.println(obj.top());
				break;
			case "size":
				System.out.println(obj.size());
				break;
			case "empty":
				System.out.println(obj.empty());
				break;
			case "pop":
				System.out.println(obj.pop());
				break;
			}
		}
	}

}