<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:

    bool static cmp(string a, string b){
        return a.length()<b.length();
    }

    string longestCommonPrefix(vector<string>& strs) {
        sort(strs.begin(),strs.end(),cmp);
        string ans = strs[0];
        for(int i=1;i<strs.size();i++){
            int j= 0;
            string same="";
            while(j<ans.length() and ans[j]==strs[i][j]){
                same+=ans[j];
                j++;
            }
            if(same==""){
                return "";
            }
            ans=same;
        }
        return ans;
    }
};
14800