<p>Given a string <code>queryIP</code>, return <code>&quot;IPv4&quot;</code> if IP is a valid IPv4 address, <code>&quot;IPv6&quot;</code> if IP is a valid IPv6 address or <code>&quot;Neither&quot;</code> if IP is not a correct IP of any type.</p>

<p><strong>A valid IPv4</strong> address is an IP in the form <code>&quot;x<sub>1</sub>.x<sub>2</sub>.x<sub>3</sub>.x<sub>4</sub>&quot;</code> where <code>0 &lt;= x<sub>i</sub> &lt;= 255</code> and <code>x<sub>i</sub></code> <strong>cannot contain</strong> leading zeros. For example, <code>&quot;192.168.1.1&quot;</code> and <code>&quot;192.168.1.0&quot;</code> are valid IPv4 addresses while <code>&quot;192.168.01.1&quot;</code>, <code>&quot;192.168.1.00&quot;</code>, and <code>&quot;192.168@1.1&quot;</code> are invalid IPv4 addresses.</p>

<p><strong>A valid IPv6</strong> address is an IP in the form <code>&quot;x<sub>1</sub>:x<sub>2</sub>:x<sub>3</sub>:x<sub>4</sub>:x<sub>5</sub>:x<sub>6</sub>:x<sub>7</sub>:x<sub>8</sub>&quot;</code> where:</p>

<ul>
	<li><code>1 &lt;= x<sub>i</sub>.length &lt;= 4</code></li>
	<li><code>x<sub>i</sub></code> is a <strong>hexadecimal string</strong> which may contain digits, lowercase English letter (<code>&#39;a&#39;</code> to <code>&#39;f&#39;</code>) and upper-case English letters (<code>&#39;A&#39;</code> to <code>&#39;F&#39;</code>).</li>
	<li>Leading zeros are allowed in <code>x<sub>i</sub></code>.</li>
</ul>

<p>For example, &quot;<code>2001:0db8:85a3:0000:0000:8a2e:0370:7334&quot;</code> and &quot;<code>2001:db8:85a3:0:0:8A2E:0370:7334&quot;</code> are valid IPv6 addresses, while &quot;<code>2001:0db8:85a3::8A2E:037j:7334&quot;</code> and &quot;<code>02001:0db8:85a3:0000:0000:8a2e:0370:7334&quot;</code> are invalid IPv6 addresses.</p>

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

<pre>
<strong>Input:</strong> queryIP = &quot;172.16.254.1&quot;
<strong>Output:</strong> &quot;IPv4&quot;
<strong>Explanation:</strong> This is a valid IPv4 address, return &quot;IPv4&quot;.
</pre>

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

<pre>
<strong>Input:</strong> queryIP = &quot;2001:0db8:85a3:0:0:8A2E:0370:7334&quot;
<strong>Output:</strong> &quot;IPv6&quot;
<strong>Explanation:</strong> This is a valid IPv6 address, return &quot;IPv6&quot;.
</pre>

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

<pre>
<strong>Input:</strong> queryIP = &quot;256.256.256.256&quot;
<strong>Output:</strong> &quot;Neither&quot;
<strong>Explanation:</strong> This is neither a IPv4 address nor a IPv6 address.
</pre>

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

<ul>
	<li><code>queryIP</code> consists only of English letters, digits and the characters <code>&#39;.&#39;</code> and <code>&#39;:&#39;</code>.</li>
</ul>

class Solution {
public:
    string validIPAddress(string queryIP) {
        bool iv4;
        int cnt=0;
        for(auto x: queryIP){
            if(x=='.'){
                iv4=true;
                if(cnt>4) return "Neither";
                cnt=0;
            }
            if(x==':'){
                iv4=false;
                break;
            }
            cnt++;
        }
        //abc
        if(iv4){
            int count=0;
            string s="";
            for(int i=0;i<queryIP.size();i++){
                if(queryIP[i]=='.'){
                    if(s.size()==0) return "Neither";
                    int x=stoi(s);
                    if(x<0 || x>255) return "Neither";
                    string flag=to_string(x);
                    if(flag!=s) return "Neither";
                    s="";
                    count++;
                }
                else if(queryIP[i]>=48 && queryIP[i]<58) s += queryIP[i];
                else return "Neither";
            }
                if(s.size()==0) return "Neither";
                int x=stoi(s);
                if(x<=0 || x>255) return "Neither";
                string flag=to_string(x);
                if(flag!=s) return "Neither";
                return count==3 ? "IPv4": "Neither";
        }
        int length = 0;
        int count = 0;
        for(int i=0;i<queryIP.length();i++)
        {
            if(queryIP[i]==':')
            {
                if(length==0 || length>4) return "Neither";
                length = 0;
                count++;
            }
            else if(queryIP[i]>=97 && queryIP[i]<=102) length++;
            else if(queryIP[i]>=65 && queryIP[i]<=70) length++;
            else if(queryIP[i]>=48 && queryIP[i]<58) length++;
            else return "Neither";

        }
        if(length==0 || length>4) return "Neither";
        return count==7 ? "IPv6" : "Neither";
        
    }
};
       
        
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