Python – Remove K length Duplicates from String

Given a String remove all K length duplicates.

Input : test_str = ‘geeksforfreeksfo’, K = 3
Output : geeksforfree
Explanation : eek, eks, ksf, sfo already in string, hence removed.

Input : test_str = ‘geeksforg’, K = 3
Output : geeksforg
Explanation : No repeated string, nothing removed.

Method : Using loop + slicing

In this, we keep track of all the K length substrs encountered, extracted using slicing, and check each time for recurrence, if occurred they are removed.

Python3

# Python3 code to demonstrate working of
# Remove K length Duplicates from String
# Using loop + slicing

# initializing strings
test_str = 'geeksforfreeksfo'

# printing original string
print("The original string is : " + str(test_str))

# initializing K
K = 3

memo = set()
res = []
for idx in range(0, len(test_str) - K):

    # slicing K length substrings
    sub = test_str[idx : idx + K]

    # checking for presence
    if sub not in memo:
        memo.add(sub)
        res.append(sub)

res = ''.join(res[ele] for ele in range(0, len(res), K))

# printing result
print("The modified string : " + str(res))

Output

The original string is : geeksforfreeksfo
The modified string : geeksforfree