Defanging an IP Address
<p>Given a valid (IPv4) IP <code>address</code>, return a defanged version of that IP address.</p>

<p>A <em>defanged&nbsp;IP address</em>&nbsp;replaces every period <code>&quot;.&quot;</code> with <code>&quot;[.]&quot;</code>.</p>

<p>&nbsp;</p>

<p><strong class="example">Example 1:</strong></p>

<pre><strong>Input:</strong> address = "1.1.1.1"

<strong>Output:</strong> "1[.]1[.]1[.]1"

</pre><p><strong class="example">Example 2:</strong></p>

<pre><strong>Input:</strong> address = "255.100.50.0"

<strong>Output:</strong> "255[.]100[.]50[.]0"

</pre>

<p>&nbsp;</p>

<p><strong>Constraints:</strong></p>

<ul>

    <li>The given <code>address</code> is a valid IPv4 address.</li>

</ul>
String
class Solution {
public:
    string defangIPaddr(string address) {
        for (int i = address.size(); i >= 0; --i) {
            if (address[i] == '.') {
                address.replace(i, 1, "[.]");
            }
        }
        return address;
    }
};