求最大回文子串（马拉车算法）

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这是正常的马拉车算法

import java.util.Scanner;public class Main {    public static void main(String[] args) {       Scanner in = new Scanner(System.in);       while (in.hasNextLine()) {        String s = in.nextLine();        System.out.println(manacher(s));          }    }    public static int manacher(String s) {        int count =0;//记录最大回文        StringBuffer sb = new StringBuffer();        char[] c =s.toCharArray();        sb.append("#");        //对字符串进行封装        for (int i = 0; i < c.length; i++) {           sb.append(c[i]);           sb.append("#");        }        int[] rad = new int[sb.length()];//记录新字符串以每个字符为中心的最大回文半径        char[] cl = sb.toString().toCharArray();        int max=0;//记录已经搜寻到的回文半径能到达右端的最达大值        int id=0;//记录回文半径能到达最有端的回文字符串的中心        for (int i = 1; i < cl.length; i++) {           if (max>i) {               rad[i]=Math.min(rad[2*id-i], max-i);           }else {               rad[i]=1;           }           while (i-rad[i]>=0 && i+rad[i]<cl.length && cl[(i-rad[i])]==cl[(i+rad[i])]) {               rad[i]++;           }           if (i+rad[i]>max) {               max=i+rad[i];               id=i;           }           count=Math.max(count, rad[i]-1);        }        return count;     }}

下面这个是我写的算法，运行起来没有上面的效率好，但是重在好理解

import java.util.Scanner;public class 回文字符串 {    public static void main(String[] args) {        Scanner sc = new Scanner(System.in);        while(sc.hasNext()){            String str1 = sc.nextLine();            MaxHuiwen(str1);        }    }    public static void MaxHuiwen(String s){        int count  = 0;        StringBuffer sb = new StringBuffer();        char[] c = s.toCharArray();        sb.append("#");        for (int i = 0; i < c.length; i++) {            sb.append(c[i]);            sb.append("#");        }        int rad[] = new int[sb.length()];        char cl[] = sb.toString().toCharArray();        int max = 0;        int id = 0;        for (int i = 1; i < cl.length; i++) {            rad[i] = 1;            while(i-rad[i]>=0 && i+rad[i]<cl.length && cl[(i-rad[i])]==cl[(i+rad[i])]) {                rad[i] ++;            }            if(i + rad[i] > max){                max = i + rad[i];                id = i;            }            count = Math.max(count, max);        }        System.out.println(count);    }    public static void MaxHuiwen(String str1, String str2){        int alen = str1.length() + 1;        int blen = str2.length() + 1;        int c[][] = new int[alen][blen];        int max = 0;        for (int i = 1; i < alen; i++) {            for (int j = 1 ; j < blen; j++) {                if(str1.charAt(i - 1) == str2.charAt(j - 1))                    c[i][j] = c[i - 1][j - 1] + 1;                else                    c[i][j] = 0;                if(c[i][j] > max)                    max = c[i][j];            }        }        System.out.println(max);    }}

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