Leetcode:Longest Common Prefix 最长公共前缀

class Solution {
public:
    string longestCommonPrefix(vector<string> &strs) {
        if (strs.size() == 0) return "";
        string res;
        for (int i = 0; ; ++i) {
            int j = 0;
            for (j = 0; j < strs.size(); ++j) {
                if (i >= strs.at(j).size() || strs.at(0).at(i) != strs.at(j).at(i)) break;
            }
            if (j < strs.size()) break;
            res += strs.at(0).at(i);
        }
        return res;
    }
};