<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>

#include <iostream>

class Solution {
public:
    std::string repeat(const std::string& str, int times) {
        std::string result;
        result.reserve(str.size() * times);
        for (int i = 0; i < times; ++i) {
            result += str;
        }
        return result;
    }
    string gcdOfStrings(string str1, string str2) {




        std::string tmp = "";
        int a = str1.length();
        int b = str2.length();
        int t = min(a, b);
        std::string tmp1 = "";
        for(int i = 0; i<t; i ++){
            if(str1[i] != str2[i]){
                return "";
            }

            tmp += str1[i];
            if (repeat(tmp, int(a/(i+1))) == str1 && repeat(tmp, int(b/(i+1))) == str2){
                tmp1 = tmp;
            }
        }

        return tmp1;
        
    }
};
30958