LeetCode 1108. Defanging an IP Address

Description

https://leetcode.com/problems/defanging-an-ip-address/

Given a valid (IPv4) IP address, return a defanged version of that IP address.

A defanged IP address replaces every period "." with "[.]".

Example 1:

Input: address = "1.1.1.1"
Output: "1[.]1[.]1[.]1"

Example 2:

Input: address = "255.100.50.0"
Output: "255[.]100[.]50[.]0"

Constraints:

• The given address is a valid IPv4 address.

Explanation

Replace with “[.]” when encountering “.”.

Python Solution

class Solution:
    def defangIPaddr(self, address: str) -> str:
        results = ""
        
        for addr in address:
            if addr == '.':
                results += "[.]"
            else:
                results += addr
                
        return results

• Time complexity: O(N).
• Space complexity: O(N).