Longest Common Prefix

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

class Solution {
public:
     string longestCommonPrefix(vector< string> &strs) 
    {
         if(strs.size()== 0)  return  "";
        
         string prefix= "";
         int maxlen=strs[ 0].length();
         for( int i= 1;i<strs.size();i++)
             if(strs[i].length()<maxlen)
                maxlen=strs[i].length();
        
         for( int i= 0;i<maxlen;i++)
        {
             char c=strs[ 0][i];
             for( int j= 1;j<strs.size();j++)
             if(strs[j][i]!=c)
                 return prefix;
            prefix=prefix+c;
        }
         return prefix;
    }
};