14. longest common prefix



Leetcode
greedy algorithm

Write a function to find the longest common prefix string amongst an array of strings.

```python
class Solution:
def longestCommonPrefix(self, strs):
"""
:type strs: List[str]
:rtype: str
"""
# 空的列表
if strs == []:
return ""

    lcp = ""
    small_length = len(strs[0])
    for str in strs:
        if len(str) < small_length:
            small_length = len(str)

    # 全部都是空字符串
    if small_length == 0:
        return ""

    print(small_length)
    for i in range(small_length):
        lcp += strs[0][i]
        for str in strs:
            # 该字符不符合最大子字符串
            if str[i] != lcp[i]:
                return lcp[0:i]
    #全部符合
    return lcp

```