manacher求最长回文子串算法模板

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <stdio.h>
#include <string>
#include <math.h>
#include <stdlib.h>
using namespace std;
int p[maxn];
char s[maxn];
void manacher(char *s){//时间复杂度O(n)
    int len=strlen(s);
    for(int i=len;i>=0;i--){
        s[i+i+2]=s[i];
        s[i+i+1]=‘#‘;
    }
    s[0]=‘*‘;
    int k=1,maxlen=0;
    for(int i=2;i<len+len+1;i++){
        int maxr=k+p[k]-1;
        p[i]=min(p[2*k-i],max(maxr-i+1,1));
        while(s[i-p[i]]==s[i+p[i]])++p[i];
        if(i+p[i]>k+p[k])k=i;
        if(p[i]>maxlen)maxlen=p[i];
    }
    printf("%d\n",maxlen-1);
}
int main()
{
    while(scanf("%s",s)!=EOF){
        manacher(s);
    }
    return 0;
}