DilianaS 3 Точки

## 5. Balanced Brackets -> Python

Здравейте колеги,

имам затруднения с 5-та задача от допълнителните към темата Data Types and Variables. Ако може да ми дадете някоя насока в коя посока на мислене да тръгна?

Благодаря предварително, Диляна

## 1.   Balanced Brackets

You will receive n lines. On those lines, you will receive one of the following:

• Opening bracket – “(“,
• Closing bracket – “)” or
• Random string

Your task is to find out if the brackets are balanced. That means after every closing bracket should follow an opening one. Nested parentheses are not valid, and if two consecutive opening brackets exist, the expression should be marked as unbalanced.

### Input

• On the first line, you will receive – the number of lines, which will follow
• On the next lines, you will receive “(”, “)” or another string

### Output

You have to print “BALANCED”, if the parentheses are balanced and “UNBALANCED” otherwise.

### Constraints

• will be in the interval [1…20]
• The length of the stings will be between [1…100] characters

### Examples

 Input Output Input Output 8 ( 5 + 10 ) * 2 + ( 5 ) -12 BALANCED 6 12 * ) 10 + 2 - ( 5 + 10 ) UNBALANCED

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MartinBG 3827 Точки

Две примерни решения на проблема:

``````lines = int(input())

is_balanced = True
last_bracket = ''
for _ in range(0, lines):
current = input()
if current not in ['(', ')']:
continue

if last_bracket == '' and current == ')' or last_bracket == current:
is_balanced = False
break

last_bracket = current

if is_balanced:
print('BALANCED')
else:
print('UNBALANCED')``````
``````lines = int(input())

is_balanced = True
has_open_bracket = False

for _ in range(0, lines):
line = input()
if line != '(' and line != ')':
continue

is_open_bracket = line == '('
if has_open_bracket == is_open_bracket:
is_balanced = False
break

has_open_bracket = is_open_bracket

if is_balanced:
print('BALANCED')
else:
print('UNBALANCED')
``````

0
02/02/2021 21:29:47