题解 | #密码截取#

package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strings"
)

func main() {
	// input
	// var input string
	// fmt.Scanf("%s\n", &input)
    inputReader := bufio.NewReader(os.Stdin)
    input, err := inputReader.ReadString('\n')
    if err == io.EOF {
        return
    }
    input = strings.Trim(input, "\r\n")
	// 从最大程度开始sliding window, 直到找到对称字符串
    l := len(input)
    for i:=0; i<l; i++ {
        for j:=0;j<=i; j++ {
            window := input[j:l-i+j]
            if isSymmetry(window) {
                fmt.Println(len(window))
                return
            }
        }
    }
}

func isSymmetry(s string) bool {
	l := len(s)
	for i, j := 0, l-1; i < j; i, j = i+1, j-1 {
		if s[i] != s[j] {
			return false
		}
	}
	return true
}