[백준/BOJ] 1874. 스택 수열 [Silver 3]

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

code

#include <iostream>
#include <vector>
#include <stack>
using namespace std;

int main()
{
	int n, index = 0;
	cin >> n;
	vector<int>seq(n);
	vector<int> v;
	vector<char> cv;
	
	for (int i = 0; i < n; i++)
		cin >> seq[i];

	for (int i = 0; i < n; i++)
	{
		v.push_back(i+1);
		cv.push_back('+');

		while (!v.empty() && v.back() == seq[index])
		{
			v.pop_back();
			cv.push_back('-');
			index++;
		}
	}
	if (v.empty())
		for (int i = 0; i < 2*n; i++)
			cout << cv[i] << '\n';
	else
		cout << "NO";

	return 0;
}

코드로 구현하는데 조금 애먹었다.. 왜캐헷갈리지