Leetcode | 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) {
        if (strs.empty()) return "";
        if (strs.size() == 1) return strs[0];
        for (int len = 0; ; len++) {
            for (int i = 1; i < strs.size(); ++i) {
                if (len >= strs[i].length() || len >= strs[i - 1].length() || strs[i][len] != strs[i - 1][len]) {
                    if (len > 0) return strs[0].substr(0, len);
                    else return "";
                }
            }
        }
        return "";
    }
};