Python3最长回文子串算法示例

class Solution:  def longestPalindrome(self, s):    """    :type s: str    :rtype: str    """    if len(s) == 1:      return s    re = s[0]    for i in range(0,len(s)-1):      for j in range(i+1,len(s)):        sta = i        end = j        flag = True        while sta < end:          if s[sta] != s[end]:            flag = False            break          sta += 1          end -= 1        if flag and j-i+1 > len(re):          re = s[i:j+1]    return re

class Solution:  def longestPalindrome(self, s):    """    :type s: str    :rtype: str    """    k = len(s)    matrix = [[False for i in range(k)] for j in range(k)]     re = s[0:1]    for i in range(k):      for j in range(k):        if i==j:          matrix[i][j] = True    for t in range(1,len(s)):       #分别考虑长度为2~len-1的子串（长串依赖短串的二维数组值）      for i in range(k):        j = i+t        if j >= k:           break        if i+1 <= j-1 and matrix[i+1][j-1]==True and s[i] == s[j]:          matrix[i][j] = True          if t+1 > len(re):            re = s[i:j+1]        elif i+1 == j and j-1 == i and s[i] == s[j]:          matrix[i][j] = True          if t+1 > len(re):            re = s[i:j+1]    return re