题解 | #密码截取#

package main

import (
	"fmt"
)

func isPalindrome(s string) bool {
	// 判断字符串是否是回文串
	left := 0
	right := len(s) - 1
	for left < right {
		if s[left] != s[right] {
			return false
		}
		left++
		right--
	}
	return true
}
func findLongestPalindrome(s string) int {
	// 找出最长的有效密码串
	maxLength := 0
	for i := 0; i < len(s); i++ {
		for j := i; j < len(s); j++ {
			substring := s[i : j+1]
			if isPalindrome(substring) && len(substring) >= maxLength {
				maxLength = len(substring)
			}
		}
	}
	return maxLength
}
func main() {
	var s string
	fmt.Scanln(&s)
	maxLength := findLongestPalindrome(s)
	fmt.Println(maxLength)
}