leetcode[14]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) {
       int lenOfstrs= strs.size();
       if(!lenOfstrs)return "";
       string Prefix=strs[0];
       for(int i=1;i<lenOfstrs;i++)
       {
           if(Prefix.length()==0||strs[i].length()==0)
              return "";
           int len=min(Prefix.length(),strs[i].length());
           int j=0;
           for(;j<len;j++)
           {
               if(Prefix[j]!=strs[i][j])
                 break;
           }
           Prefix=Prefix.substr(0,j);
       }
       return Prefix;
    }
};