HDU - 3068 最长回文(manacher)

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=3068

求最长回文串，manacher算法。具体可以看转载的blog，代码如下：

#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <algorithm>
using namespace std;

char line[220020],s[220020];
int Mp[110010*2];

void Manacher(int len){
int l = 0;
s[l++] = '$';
s[l++] = '#';
for(int i = 0;i < len;i ++){
s[l++] = line[i];
s[l++] = '#';
}

int id = 0, mx = 0;
for(int i = 1;i < l;i ++){
Mp[i] = mx > i ? min(Mp[2*id-i],mx-i) : 1;
while(s[i + Mp[i]] == s[i - Mp[i]]) Mp[i]++;
if(i + Mp[i] > mx){
mx = i+Mp[i];
id = i;
}
}
}

int main()
{
while(scanf("%s",&line) != EOF){
//memset(Mp,0,sizeof(Mp));

int ans = 0;
int le = strlen(line);
Manacher(le);

for(int i = 0;i < le*2+2;i ++)
ans = max(ans,Mp[i] - 1);
cout<<ans<<endl;
}
return 0;
}