Python: Find the index of the matching parentheses for each character in a given string

Python Programming Puzzles: Exercise-84 with Solution

Write a Python program to find the index of the matching parentheses for each character in a given string.

Input:  
()(())
Output:
[1, 0, 5, 4, 3, 2]

Input:  
()()()
Output:
[1, 0, 3, 2, 5, 4]

Input:  
((()))
Output:
[5, 4, 3, 2, 1, 0]

Pictorial Presentation:

Sample Solution:

Python Code:

#License: https://bit.ly/3oLErEI

def test(parens):
    a = list(parens)
    stack = []
    for i, c in enumerate(a):
        if c == "(":
            stack.append(i)
        else:
            a[stack[-1]] = i
            a[i] = stack.pop()
    return a 

parens = "()(())"
print("Original parentheses:",parens) 
print("Index of the matching parentheses for each character in a given string:")
print(test(parens))
parens = "()()()"
print("\nOriginal parentheses:",parens) 
print("Index of the matching parentheses for each character in a given string:")
print(test(parens))
parens = "((()))"
print("\nOriginal parentheses:",parens) 
print("Index of the matching parentheses for each character in a given string:")
print(test(parens))

Sample Output:

Original parentheses: ()(())
Index of the matching parentheses for each character in a given string:
[1, 0, 5, 4, 3, 2]

Original parentheses: ()()()
Index of the matching parentheses for each character in a given string:
[1, 0, 3, 2, 5, 4]

Original parentheses: ((()))
Index of the matching parentheses for each character in a given string:
[5, 4, 3, 2, 1, 0]

Flowchart:

Python Code Editor :

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