Leetcode 14. Longest Common Prefix

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string result = "";
        if(strs.size() == 0) {
            return result;
        }
        string pattern = strs[0];
        for(int i = 0; i < pattern.length(); i++) {
            char ch = pattern[i];
            for(string s : strs) {
                if(s[i] != ch) {
                    return result;
                }
            }
            result += ch;
        }
        return result;
    }
};