题解 | #最长回文子串#

# !/usr/bin/env python3
# -*- coding: utf-8 -*-
__author__ = 'tianyi'
__date__ = '2024/3/23 20:24 '
__file__ = 'HW_HJ85.py'
import sys
for i in sys.stdin:
    a = i.rstrip()
    list1 = []
    for j in range(0, len(a)-1):
        if a[j] == a[j+1]:
            string1 = a[j]+a[j+1]
            n=0
            for k in range(j+2, len(a)):
                n-=1
                try:
                    if a[k] == a[j+n]:
                        string1 = a[k]+string1+a[j+n]
                    else:
                        break
                except:
                    pass
            list1.append(string1)
        else:
            try:
                if a[j-1] == a[j+1]:
                    string1 = a[j-1]+a[j]+a[j+1]
                    n=-1
                    for k in range(j+2, len(a)):
                        n-=1
                        try:
                            if a[k] == a[j+n]:
                                if j+n < 0:
                                    break
                                string1 = a[k]+string1+a[j+n]
                            else:
                                break
                        except:
                            pass
                    list1.append(string1)
            except:
                pass
    list1.sort(key=len,reverse = True)
    print(len(list1[0]))

sort函数是在原列表进行排序更改， 不存在返回值