python版：

class Solution:
    def longestPalindrome(self, s):
        """
        :type s: str
        :rtype: str
        """
        start = end = 0
        for i in range(len(s)): 
            len1 = self.find(s,i,i) #aba
            len2 = self.find(s,i,i+1) #abba
            maxlen = max(
 
len1,len2)
            if maxlen>end-start+1:
                start = i-(maxlen-1)//2
                end = i+maxlen//2
        return s[start:end+1]
           
        
    def find(self,s,left,right):
        while(left>=0 and right<len(s) and s[left]==s[right]):
                left-=1
                right+=
 
1
        return right-left-1

【總結】：
python中的 / 是浮點除法
// 是整除