programmers_택배상자_java

https://school.programmers.co.kr/learn/courses/30/lessons/131704

프로그래머스

import java.util.*;

class Solution {
    public int solution(int[] order) {
        int answer = 0;
        int orderLength = order.length;
        
        Stack<Integer> subContainer = new Stack<>();
        int idx = 0; 
        for(int i = 1; i<= orderLength; i++){
            subContainer.push(i);
            while(!subContainer.isEmpty()){
                if(subContainer.peek() == order[idx]){
                    subContainer.pop();
                    answer++;
                    idx++;
                }else{
                    break;
                }
            }
        }
        
        return answer;
    }
}