class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        if (!strs.size())
            return "";
        int sz = strs.size(), min_len = INT_MAX, min_len_index, pointer;
        for (int i = 0; i < sz; ++i)
        {
            if (strs[i].size() < min_len)
            {
                min_len = strs[i].size();
                min_len_index = i;
            }
        }

        pointer = strs[min_len_index].size() - 1;
        for (int i = 0; i < sz && pointer >= 0; ++i)
        {
            int j = 0;
            while (j <= pointer && strs[i][j] == strs[min_len_index][j])
                ++j;
            --j;
            if (j < pointer)
                pointer = j;
        }
        return strs[min_len_index].substr(0, pointer + 1);
    }
};