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) {
        string result = "";
        if

(strs.empty()) return

 result;
        for(int i = 0; 

i < strs[0].size();

 i++)
        {
            for(int j = 1; j < strs.size(); j++)
            {
                if(strs[j - 1][i] != strs[j][i])
                    return result;
            }
            result += strs[0][i];
        }
        return result;
    }
};

• 一定要注意：strs[0].size()；默认了strs[0]存在；所以前面必须先测试strs非空，否则会读到未定义内存