<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 {
public:
    bool isDivisor(int gcdLen, int str1Len, int str2Len, string str1, string str2){
        if(str1Len % gcdLen || str2Len % gcdLen){
            // Check if gcdLen is a factor of the original strings
            return false;
        }

        int factor1 = str1Len / gcdLen;
        int factor2 = str2Len / gcdLen;

        string newStr1 = "";
        string newStr2 = "";
        
        for(int i = 0; i < factor1; i++){
            newStr1 += str1.substr(0, gcdLen);
        }

        for(int i = 0; i < factor2; i++){
            newStr2 += str1.substr(0, gcdLen);
        }
        
        return (newStr1 == str1 && newStr2 == str2);
    }

    string gcdOfStrings(string str1, string str2) {
        int len1 = str1.size();
        int len2 = str2.size();
        string res = "";
        
        for(int i = min(len1, len2); i > 0; i--){
            if(isDivisor(i, len1, len2, str1, str2)){
                res = str1.substr(0, i);
                return res; 
            }
        }

        return res;
    }
};
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