14. Longest Common Prefix

class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        ans = ""
        for j in range(300):
            flag = True
            for i in range(len(strs)):
                if j >= len(strs[i]):
                    flag = False
                    break
                if strs[i][j] != strs[0][j]:
                    flag = False
                    break
            if flag:
                ans = ans + strs[0][j]
            else:
                break
        return ans