<p>Write a function to find the longest common prefix string amongst an array of strings.</p>

<p>If there is no common prefix, return an empty string <code>&quot;&quot;</code>.</p>

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

<pre>
<strong>Input:</strong> strs = [&quot;flower&quot;,&quot;flow&quot;,&quot;flight&quot;]
<strong>Output:</strong> &quot;fl&quot;
</pre>

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

<pre>
<strong>Input:</strong> strs = [&quot;dog&quot;,&quot;racecar&quot;,&quot;car&quot;]
<strong>Output:</strong> &quot;&quot;
<strong>Explanation:</strong> There is no common prefix among the input strings.
</pre>

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

<ul>
	<li><code>1 &lt;= strs.length &lt;= 200</code></li>
	<li><code>0 &lt;= strs[i].length &lt;= 200</code></li>
	<li><code>strs[i]</code> consists of only lowercase English letters.</li>
</ul>

class Solution {
public:
    static bool comparator(string str1, string str2){
        return str1.size() < str2.size();
    }
    string longestCommonPrefix(vector<string>& strs) {
        string substring = "";
        sort(strs.begin(),strs.end(),comparator);
        // the largest prefix can be of the strs[0]
        string prefix = strs[0];
        int flag = 0;
        while(prefix.size() >= 0){
            flag = 0;
            for(int i = 1; i < strs.size(); i++){
                if(prefix == strs[i].substr(0,prefix.size())){
                    flag++;
                    continue;
                }
                else{
                    break;
                }
            }
            if(flag == strs.size()-1){
                return prefix;
            }
            prefix = prefix.substr(0,prefix.size()-1);
        }
        return "";
    }
};
14600