모항 2022. 4. 12. 23:06

풀이방법

사용된 것:

Stack

switch-case

 

2022.04.12

간단한 스택 문제이다.

switch-case문을 사용하여 풀었다.

 

코드

Java(2022.04.12)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Stack;
import java.util.StringTokenizer;

public class Main {

	public static void main(String[] args) throws IOException{
		// TODO Auto-generated method stub
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		
		Stack<Integer> stack = new Stack<Integer>();
		
		int n = Integer.parseInt(br.readLine());
		
		StringBuilder sb = new StringBuilder();
		for(int i = 0; i<n; i++) {
			StringTokenizer st = new StringTokenizer(br.readLine());
			
			String command = st.nextToken();
			
			switch(command) {
			case "push" : stack.add(Integer.parseInt(st.nextToken())); break;
			case "pop" : if(stack.isEmpty()) sb.append(-1);
						else sb.append(stack.pop());
						sb.append(System.lineSeparator()); break;
			case "size" : sb.append(stack.size()); sb.append(System.lineSeparator()); break;
			case "empty" : if(stack.isEmpty()) sb.append(1);
						else sb.append(0);
						sb.append(System.lineSeparator()); break;
			case "top" : if(stack.isEmpty()) sb.append(-1);
						else sb.append(stack.peek());
						sb.append(System.lineSeparator()); break;
			}
		}
		
		System.out.print(sb);
	}

}