Python | Ways to determine common prefix in set of strings

Given a set of strings, write a Python program to determine common prefix from a set of strings. Given below are a few methods to solve the above task.
Method #1: Using Naive Approach

Python3

# Python code to demonstrate
# to find common prefix
# from set of strings

# Initialising string
ini_strlist = ['akshat', 'akash', 'akshay', 'akshita']

# Finding common prefix using Naive Approach
res = ''
prefix = ini_strlist[0]

for string in ini_strlist[1:]:
    while string[:len(prefix)] != prefix and prefix:
        prefix = prefix[:len(prefix)-1]
    if not prefix:
        break
res = prefix

# Printing result
print("Resultant prefix", str(res))

Output:

Resultant prefix ak

Method #2: Using itertools.takewhile and zip

Python3

# Python code to demonstrate
# to find common prefix
# from set of strings

from itertools import takewhile

# Initialising string
ini_strlist = ['akshat', 'akash', 'akshay', 'akshita']

# Finding common prefix using Naive Approach
res = ''.join(c[0] for c in takewhile(lambda x:
        all(x[0] == y for y in x), zip(*ini_strlist)))

# Printing result
print("Resultant prefix", str(res))

Output:

Resultant prefix ak

Complexity Analysis:

In both the solution time and space complexity are the same:

Time Complexity: O(n²)

Space Complexity: O(n)