The Check for Redundant Brackets problem involves checking if an expression contains any redundant brackets. Redundant brackets are those which enclose a subexpression that doesn't need to be enclosed. This can be efficiently solved using a stack to track operators and brackets.
Consider an expression containing brackets and operators:
"((a+b))"
To check for redundant brackets using a stack, follow these steps:
After performing these steps, determine if the expression contains redundant brackets:
Input: "((a+b))"
Output: True (The brackets are redundant)
Consider the input expression "((a+b))". We want to check if it contains redundant brackets.
Function check_redundant_brackets(expression):
# Initialize an empty stack
stack = []
# Traverse the expression
For char in expression:
If char == ')':
top = stack.pop()
elements_inside = 0
While top != '(': # Check characters inside the brackets
elements_inside += 1
top = stack.pop()
If elements_inside <= 1: # If no operators or single operand inside
Return True
Else:
stack.append(char)
Return False
def check_redundant_brackets(expression):
# Initialize an empty stack
stack = []
# Traverse the expression
for char in expression:
if char == ')':
top = stack.pop()
elements_inside = 0
while top != '(': # Check characters inside the brackets
elements_inside += 1
top = stack.pop()
if elements_inside <= 1: # If no operators or single operand inside
return True
else:
stack.append(char)
return False
# Example usage:
input_expression = "((a+b))"
print(f"Input expression: {input_expression}") # Output: Input expression: ((a+b))
has_redundant_brackets = check_redundant_brackets(input_expression)
print(f"Contains redundant brackets: {has_redundant_brackets}") # Output: Contains redundant brackets: True
This Python program defines a function check_redundant_brackets
that uses a stack to check if an expression contains redundant brackets. The function iterates through the expression, uses the stack to track characters, and identifies redundant brackets by checking the number of elements between matching brackets.