[백준]1874-스택 수열(설명X)

#include <cstdio>
#include <stack>
using namespace std;
 
int main()
{
    int n, cur = 1;
    bool inc = true;
    scanf("%d", &n);
    stack<int> stk;
    stk.push(0);
    deque<char> c_stk;
    for (size_t i = 0; i < n; i++) {
        int num;
        scanf("%d", &num);
        if (stk.top() < num) {
            for (size_t j = cur; j <= num; j++) {
                c_stk.push_back('+');
                stk.push(j);
                cur++;
            }
            stk.pop();
            c_stk.push_back('-');
        }
        else if (stk.top() == num) {
            stk.pop();
            c_stk.push_back('-');
        }
        else {
            printf("NO");
            return 0;
        }
    }
    size_t size = c_stk.size();
    for (size_t i = 0; i < size; i++) {
        printf("%c\n", c_stk.front());
        c_stk.pop_front();
    }
    return 0;
}