leetcode 14. Longest Common Prefix

/*leetcode 14. Longest Common Prefix解题思路：找出每两个字符之间的公共前缀，然后让这个公共前缀为一个字符与后面的比较*/#include <iostream>#include <string>#include <vector>using namespace std;class Solution {public:    string longestCommonPrefix(vector<string>& strs)     {        if (strs.size() == 0)            return "";        string ret = strs[0];       //prefix,先设定为第一个字符，然后与后面的每一个字符比较，找公共前缀        int len;        for (int i = 1; i < strs.size(); ++i)        {            len = ret.size() < strs[i].size() ? ret.size() : strs[i].size();            if (len == 0)                return "";            int index= 0;           //前缀匹配的长度            for (; index < len; ++index)                if (ret[index] != strs[i][index])                    break;            ret = ret.substr(0, index);            /*            substr的原型为：substr（size_type off,size_type count)            off为string中的偏移量，count为截取的字符串的个数            */            //cout << ret << endl;        }        return ret;    }};void test_longestCommonPrefix(){    Solution sol;    vector<string> vstr{ "abcdefg", "abcdefghij", "abcde", "abcd" };    sol.longestCommonPrefix(vstr);}int main(){    test_longestCommonPrefix();    return 0;}