Leetcode 14 Longest Common Prefix

最长公共子串，我使用的方法是枚举

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string ans = "";
        if (strs.size() != 0)
            {for (int i = 0; i< strs[0].size(); ++i )
            {
                bool flg = false;
                ans = strs[0].substr(0,i+1);
                for (int j = 1; j < strs.size();++j)
                {
                    if(strs[j].substr(0,i+1) != ans) {
                        flg = true;
                        break;
                    }
                }
                if(flg) {
                    ans = ans.substr(0,i);break;
                }
            }
            
        }
        return ans;
    }
};