<p>For two strings <code>s</code> and <code>t</code>, we say &quot;<code>t</code> divides <code>s</code>&quot; if and only if <code>s = t + t + t + ... + t + t</code> (i.e., <code>t</code> is concatenated with itself one or more times).</p>

<p>Given two strings <code>str1</code> and <code>str2</code>, return <em>the largest string </em><code>x</code><em> such that </em><code>x</code><em> divides both </em><code>str1</code><em> and </em><code>str2</code>.</p>

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

<pre>
<strong>Input:</strong> str1 = &quot;ABCABC&quot;, str2 = &quot;ABC&quot;
<strong>Output:</strong> &quot;ABC&quot;
</pre>

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

<pre>
<strong>Input:</strong> str1 = &quot;ABABAB&quot;, str2 = &quot;ABAB&quot;
<strong>Output:</strong> &quot;AB&quot;
</pre>

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

<pre>
<strong>Input:</strong> str1 = &quot;LEET&quot;, str2 = &quot;CODE&quot;
<strong>Output:</strong> &quot;&quot;
</pre>

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

<ul>
	<li><code>1 &lt;= str1.length, str2.length &lt;= 1000</code></li>
	<li><code>str1</code> and <code>str2</code> consist of English uppercase letters.</li>
</ul>

class Solution {
    bool isDivider(const string& devider, const string& str)
    {
        int sizeDev = devider.length();
        int sizeStr = str.length();
        
        if(sizeStr%sizeDev!=0)
            return false;

        int numberOfIterations = sizeStr/sizeDev;
        string temp;
        for(int i=0;i<numberOfIterations;i++)
        {
            temp += devider;
        }
        
        return temp==str;
    }
public:
    string gcdOfStrings(string str1, string str2) {
        string toReturn;

        int size = str1.size()<str2.size()?str1.size() : str2.size();
        for(int i=1;i<=size;i++)
        {
            if(str1.size()%i!=0)
                continue;
            string temp = str1.substr(0,i);
            if(isDivider(temp,str2) && isDivider(temp,str1))
                toReturn = temp;
        }

        return toReturn;
    }
};
11580