[백준1874] 스택 수열 Java

https://www.acmicpc.net/problem/1874

1874번: 스택 수열

 

package Chapter1;

import java.util.Scanner;
import java.util.Stack;

public class BJ1874 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] arr = new int[n];

        int num = 0;

        Stack<Integer> stack = new Stack<>();
        while (n > 0) {
            int value = sc.nextInt();

            if (value > num) {
                for (int i=num+1; i<=value; i++) {
                    stack.push(i);
                    System.out.println("+");
                }
                num = value;
            }

            else if (stack.peek() != value) {
                System.out.println("NO");
                return;
            }

            stack.pop();
            System.out.println("-");
        }
    }
}