[백준][스택] 1873. 스택 수열 (파이썬/Python)

n = int(input())
stack = []
result = []
check = True
cur = 1

for i in range(n):
    num = int(input())
    while cur <= num:       
        stack.append(cur)
        result.append("+")
        cur += 1
    if stack[-1] == num:   
        stack.pop()        
        result.append("-")
    else:                  
        print("NO")        
        check = False           
        break               

if check == True:
    for i in result:
        print(i)