Please help me in this code!

Question

Parentheses are balanced, if all opening parentheses have their corresponding closing parentheses.

Given an expression as input, we need to find out whether the parentheses are balanced or not.
For example, "(x+y)*(z-2*(6))" is balanced, while "7-(3(2*9))4) (1" is not balanced.

The problem can be solved using a stack.
Push each opening parenthesis to the stack and pop the last inserted opening parenthesis whenever a closing parenthesis is encountered.
If the closing bracket does not correspond to the opening bracket, then stop and say that the brackets are not balanced.
Also, after checking all the parentheses, we need to check the stack to be empty -- if it's not empty, then the parentheses are not balanced.

Implement the balanced() function to return True if the parentheses in the given expression are balanced, and False if not.

Sample Input:
(a( ) eee) )

Sample Output:
False

Answer 1

# Function to test balanced brackets
def BalancedBrackets(Str):
# stack for storing opening brackets
stack = []

# Loop for checking string
for char in Str:
# if its opening bracket, so push it in the
# stack
if char == '{' or char == '(' or char == '[':
stack.append(char) # push
# else if its closing bracket then
# check if the stack is empty then return false or
# pop the top most element from the stack
# and compare it
elif char == '}' or char == ')' or char == ']':
if len(stack) == 0:
return False
top_element = stack.pop() # pop
# function to compare whether two
# brackets are corresponding to each other
if not Compare(top_element, char):
return False
# lastly, check that stack is empty or not
if len(stack) != 0:
return False

return True

# Function to check two corresponding brackets
# equal or not.
def Compare(opening, closing):
if opening == '(' and closing == ')':
return True
if opening == '[' and closing == ']':
return True
if opening == '{' and closing == '}':
return True
return False

# Test function
exp=input()
print(BalancedBrackets(exp))
#print(BalancedBrackets("{123(456[.768])}"))

Answer 2

brackets=[]
for char in expression:
if char is openingbracket:
push it to brackets
elif char is closingbracket
pop brackets or False

brackets should be an empty list now

Answer 3

Well, Goto leetcode(webpage) and submit your solution ,if failed try again....

Stack..= >

Here it is,

Just ignore all stuff rather '('[open parenthesis] and ')' [close parenthesis]

so First : you need create a loop first ,which will terminate when you reach at the end of your string...

if '(' encountered push it in your stack;;;

if ')' encountered pop from your stack only if it is not empty... else it's just imbalanced as there is no '(' to match ')' so just return false ;;;

after the end of loop check your stack, if it is empty it means all parenthesis are balanced return true else return false....

Well,It's you one who should implement it....

Answer 4

Muthu kumar.V

Show your code.

Answer 5

#Right and here

def balanced(expression):
count = 0
for char in expression:
if char == "(":
count += 1
elif char == ")":
if count == 0:
return False
count -= 1
return count == 0

print(balanced(input()))

Answer 6

Qusi AL-Hejazi

Use Push and Pop technique.

Answer 7

The code doesn't run please give a correct code

Answer 8

I tried it but code doesn't run.it indicates some errors ☹️

Answer 9

When u call pila.pop() u must check the return
If it is False u must return False

Answer 10

def balanced(expression):
#your code goes here
li=[]
flag=0
for i in expression:
if len(li)==0 and i==")":
flag=1
elif i==")":
li.remove("(")
elif i=="(":
li.append("(")
if len(li)==0 and flag==0:
return "True"
else:
return "False"

print(balanced(input()))

Answer 11

Muthu kumar.V

Why you don't try self to write a code?

Answer 12

def balanced(expression):
count = 0
for char in expression:
if char == "(":
count += 1
elif char == ")":
if count == 0:
return False
count -= 1
return count == 0

print(balanced(input()))

Answer 13

Hi all!
I am starting in the world of programming and I am not finding the error in my code.
Of seven cases tested, only one gives an error and since I am not using the paid version it does not let me see the input to see what I can correct.
I hope you can help me.
Thanks a lot

class Stack:
def __init__(self):
self.items = []

def is_empty(self):
return self.items == []

def push(self, item):
self.items.insert(0, item)

def pop(self):
if self.items != []:
return self.items.pop(0)
else:
return False

def print_stack(self):
print(self.items)

def balanced(expression):
pila = Stack()
for i in expression:
if i == "(":
pila.push("(")
elif i == ")":
pila.pop()
if pila.items == []:
return True
else:
if pila.items != []:
return False

print(balanced(input()))

Answer 14

Thank you very much for the help!

Answer 15

here is my code:

#your code goes here
value = []
for i in expression:
if i == "(":
value.insert(0, i)
elif i == ")":
if len(value) == 0:
return("False")
elif len(value) != 0:
value.pop(0)
if value.count("(") == value.count(")"):
return("True")
elif value.count("(") != value.count(")"):
return("False")