1108 Defanging an IP Address IP 地址无效化
Description:
Given a valid (IPv4) IP address, return a defanged version of that IP address.
A defanged IP address replaces every period "." with "[.]".
Example:
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.
题目描述:
给你一个有效的 IPv4 地址 address，返回这个 IP 地址的无效化版本。
所谓无效化 IP 地址，其实就是用 "[.]" 代替了每个 "."。
示例 :
示例 1：
输入：address = "1.1.1.1"
输出："1[.]1[.]1[.]1"
示例 2：
输入：address = "255.100.50.0"
输出："255[.]100[.]50[.]0"
提示：
给出的 address 是一个有效的 IPv4 地址
思路:
遍历字符串, 按照题目要求把 “.”替换成 “[.]”即可
时间复杂度O(n), 空间复杂度O(1)
代码:
C++:
class Solution
{
public:
string defangIPaddr(string address)
{
for (int i = address.size() - 1; i > -1; --i) if (address[i] == '.') address.replace(i, 1, "[.]");
return address;
}
};
Java:
class Solution {
public String defangIPaddr(String address) {
return address.replaceAll("\\.", "[.]");
}
}
Python:
class Solution:
def defangIPaddr(self, address: str) -> str:
return address.replace(r'.', '[.]')
