Delete Characters to Make Fancy String — LeetCode 1957 Python Solution

The problem

A fancy string is a string where no three consecutive characters are equal. Given a string s, delete the minimum possible number of characters from s to make it fancy.

Example

Input

s = "leeetcode"

Output

"leetcode"

Explanation

Remove an 'e' from the first group of 'e's to create "leetcode".

Python solution

class Solution:
    def makeFancyString(self, s: str) -> str:
        ans = []
        for i, c in enumerate(s):
            if i < 2 or c != s[i - 1] or c != s[i - 2]:
                ans.append(c)
        return "".join(ans)

Complexity

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 1957. Delete Characters to Make Fancy String is filed here because the reference solution below belongs to the algorithm family this hub collects, even though its LeetCode tags point elsewhere.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

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