14. 最长公共前缀

class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        n = len(strs)
        if n == 0:
            return ''
        for i in range(len(strs[0])):
            for j in range(1, n):
                if len(strs[j]) <= i or strs[j][i] != strs[0][i]:
                    return strs[0][:i]
        return strs[0]

class Solution {
    public String longestCommonPrefix(String[] strs) {
        int n;
        if ((n = strs.length) == 0) return "";
        for (int i = 0; i < strs[0].length(); ++i) {
            for (int j = 1; j < n; ++j) {
                if (strs[j].length() <= i || strs[j].charAt(i) != strs[0].charAt(i)) {
                    return strs[0].substring(0, i);
                }
            }
        }
        return strs[0];
    }
}

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        int n;
        if ((n = strs.size()) == 0) return "";
        for (int i = 0; i < strs[0].size(); ++i) {
            for (int j = 1; j < n; ++j) {
                if (strs[j].size() <= i || strs[j][i] != strs[0][i]) {
                    return strs[0].substr(0, i);
                }
            }
        }
        return strs[0];
    }
};