<p>A <strong>valid IP address</strong> consists of exactly four integers separated by single dots. Each integer is between <code>0</code> and <code>255</code> (<strong>inclusive</strong>) and cannot have leading zeros.</p>

<ul>
	<li>For example, <code>&quot;0.1.2.201&quot;</code> and <code>&quot;192.168.1.1&quot;</code> are <strong>valid</strong> IP addresses, but <code>&quot;0.011.255.245&quot;</code>, <code>&quot;192.168.1.312&quot;</code> and <code>&quot;192.168@1.1&quot;</code> are <strong>invalid</strong> IP addresses.</li>
</ul>

<p>Given a string <code>s</code> containing only digits, return <em>all possible valid IP addresses that can be formed by inserting dots into </em><code>s</code>. You are <strong>not</strong> allowed to reorder or remove any digits in <code>s</code>. You may return the valid IP addresses in <strong>any</strong> order.</p>

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

<pre>
<strong>Input:</strong> s = &quot;25525511135&quot;
<strong>Output:</strong> [&quot;255.255.11.135&quot;,&quot;255.255.111.35&quot;]
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;0000&quot;
<strong>Output:</strong> [&quot;0.0.0.0&quot;]
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;101023&quot;
<strong>Output:</strong> [&quot;1.0.10.23&quot;,&quot;1.0.102.3&quot;,&quot;10.1.0.23&quot;,&quot;10.10.2.3&quot;,&quot;101.0.2.3&quot;]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 20</code></li>
	<li><code>s</code> consists of digits only.</li>
</ul>

class Solution {
public:

    vector<string> get_vars(string s){

        if(s == "") return {""};
        int i = 0;
        vector<string> L;
        string t = "";
        while(i < 3){

            t += s[i];
            int x = stoi(t);
            if(x <= 255 && x >= 0 && (t[0] != '0' || t.size() == 1)){

                if(i + 1 == s.size()){

                    int ct = 0;
                    for(char &ttt : t) if(ttt == '.') ct++;
                    if(ct <= 3) L.push_back(t);
                    break;

                }
                vector<string> T = get_vars(s.substr(i + 1, s.size() - i - 1));
                for(string &ss : T){


                    string tt = t + '.' + ss;

                    int ct = 0;
                    for(char &ttt : tt) if(ttt == '.') ct++;
                    if(ct <= 3)
                    L.push_back(tt);

                }

            }else break;
            i++;

        }

        return L;

    }

    vector<string> restoreIpAddresses(string s) {
        

        vector<string> L = get_vars(s);
        vector<string> ans;
        for(string &ss : L){

            int ct = 0;
            for(char &ttt : ss) if(ttt == '.') ct++;
            if(ct == 3) ans.push_back(ss);

        }
        return ans;

    }
};
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