manacher 最长回文子串 hdu3068

Manacher 算法 （马拉车）

//#include <bits/stdc++.h>
#include<stdio.h>
#include<string.h>
#include<string>
#include<math.h>
#include<algorithm>
#include<iostream>
#include<queue>
#include<vector>
#include<stack>
#include<map>
#include<set>
#include<stdlib.h>
#include<time.h>
#include <iomanip>
#define lowbit(x) (x&(-x))
#define inf  0x7fffffff
#define linf 0x7fffffffffffffff
#define fil(x,y) memset(x,y,sizeof(x))
#define fup(i,x,y) for(int i=(x);i<=(y);i++)
#define fdn(i,x,y) for(int i=(x);i>=(y);i--)
#define sp(x) setprecision(x)
#define sd(n) scanf("%d",&n)
#define sdd(n,m) scanf("%d%d",&n,&m)
#define sddd(n,m,k) scanf("%d%d%d",&n,&m,&k)
#define sld(n) scanf("%lld",&n)
#define sldd(n,m) scanf("%lld%lld",&n,&m)
#define slddd(n,m,k) scanf("%lld%lld%lld",&n,&m,&k)
#define sf(n) scanf("%lf",&n)
#define sff(n,m) scanf("%lf%lf",&n,&m)
#define sfff(n,m,k) scanf("%lf%lf%lf",&n,&m,&k)
#define sc(n) scanf("%s",n)
#define pf(x) printf("%d\n",x)
#define pfl(x) printf("%lld\n",x)
#define pff(x) printf("%lf\n",x)
#define debug printf("!!\n");
#define N 1000005
#define M 4000009
#define pi acos(-1)
#define eps 1e-2
//cout.setf(ios::fixed);
//freopen("out.txt","w",stdout);// freopen("in.txt","r",stdin);
using namespace std;
typedef long long  ll;
typedef double db;
char cc[110005];
char c[220005];
int a[220005];
int manacher()
{
int len=strlen(cc),pos=0,edge=0,maxx=0;
int n=0;
fup(i,0,len-1)
c[n++]='$',c[n++]=cc[i];
c[n++]='$';
fup(i,0,n-1)
{
if(i<edge) a[i]=min(a[pos*2-i],edge-i);
else a[i]=1;
while(i-a[i]>=0&&i+a[i]<=n-1&&c[i-a[i]]==c[i+a[i]]) a[i]++;
if(i+a[i]>edge) edge=i+a[i],pos=i;
maxx=max(maxx,a[i]);
}
return maxx-1;
}
void solve()
{
while(~sc(cc))
{
pf(manacher());
}
}
int main()
{
int t=1;
//    sd(t);
while(t--)
{
solve();
}
return 0;
}