[백준][JAVA] 1874 : 스택 수열

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

1874번: 스택 수열

import java.util.Stack;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        StringBuilder sb = new StringBuilder();
        Stack<Integer> stack = new Stack<>();
        int N = s.nextInt(), start = 0;

        while(N -- > 0) { // N--&&N<=0
            int value = s.nextInt();
            if(value > start) {
                for(int i = start + 1; i <= value; i++) {
                    stack.push(i);
                    sb.append('+').append('\n');
                }
                start = value; 
            }
            else if(stack.peek() != value) {
                System.out.println("NO");
                return;
            }
            stack.pop();
            sb.append('-').append('\n');
        }
        System.out.println(sb);
    }
}