[LeetCode] 1108. Defanging an IP Address

Description

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.

Analyse

将ip地址中的.替换成[.], 简单题

在address上直接replace，或者插入到一个新的字符串里去

string defangIPaddr(string address)
{
    for(int i = 0; i < address.size(); i++)
    {
        if (address[i] == '.')
        {
            address.replace(i, 1, "[.]");
            i+=2; //使i越过已经replace过的 .
        }
    }

    cout << address << endl;
    return address;
}

string defangIPaddr(string address)
{
    string result;
    for(int i = 0; i < address.length(); i++)
    {
        if (address[i] == '.')
        {
            result += "[.]";
        }
        else
        {
            result += address[i];
        }
    }

    return result;
}