[ 백준-1874번 / 스택 ] 스택 수열

 

1. 문제

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2. 소스코드

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#include <iostream>
#include <stack>
//#include <vector> 

using namespace std;

int n, index = 1;
stack <int> seq;
//vector <char> ans;
string ans;

int main() {

	cin >> n;

	//for (int i = 0; i < n; i++) 
    while(n--){

		int num;
		cin >> num;

		while (index <= num){
        	//seq.push(index);
        	//index++;
        	seq.push(index++);
        	ans += '+';
		}
		if (!seq.empty()) {
			if (num == seq.top()) {
				seq.pop();
				ans += '-';
			}
			else {
				cout << "NO";
				return 0;
			}
		}
		//else break;
	}
	for (char ch : ans) {
		cout << ch << '\n';
	}
	return 0;
}