回文串

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int m1=299993;
const int m2=1e9+7;
const int K=13331;
const int N=600000+10;
char b[N];
char a[N];
int p[N];
struct point{
    int num,ha;//mod 1e9+7
    int len;
}poi[N];
int n,ans;
///////////////////////////////
int nxt[N],pre[N];
int tot;
ll h1[N],h2[N];
ll jin1[N],jin2[N];
ll H(int st,int ed,int ce){
    ll ret;
    if(ce==1){
        ret=(h1[ed]+m1-h1[st-1]*jin1[ed-st+1])%m1;
    }
    else{
        ret=(h2[ed]+m2-h2[st-1]*jin2[ed-st+1])%m2;
    }
    return ret;
}
void insert(ll xi1,ll xi2){
        
}
bool check(){
        
}
void work(int st,int ed){
    ll ha1=H(st,ed,1);
    ll ha2=H(st,ed,2);
    if(!check(ha1)){
        insert(ha1,ha2);
        if(st!=ed){
        
        }//add edges
    }
    else{
        
    }//++num
}
//////////////////////////hash
void manacher(){
    int id=1,mx=0;
    p[1]=1;
    for(int i=2;i<=n;i++){
        p[i]=min(mx-i,2*id-i);
        if(p[i]<0) p[i]=0;
        int j=i-p[i],k=i+p[i];
        while(j>0&&k<n&&a[k]==a[j]){
            p[i]++;
            if(i+p[i]-1>mx){
                id=i;
                mx=i+p[i]-1;
                work(i-p[i]+1,i+p[i]-1);
            }
            j--,k++;
        }
    }
}
///////////////////////////manacher
struct node{
    int nxt,to;
}bian[2*N];
int hd[N],cnt;
int du[N];
void add(int x,int y){
    bian[++cnt].nxt=hd[x];
    bian[cnt].to=y;
    hd[x]=cnt;
    du[y]++;
}
int q[N];
int 
void topo(){
}
//////////////////////////topu
int main()
{
    scanf("%s",b+1);
    int m=strlen(b+1);
    for(int i=1;i<=m;i++) a[++n]='#',a[++n]=b[i];
    a[++n]='#';
    jin1[0]=1;jin2[0]=1;
    for(int i=1;i<=n;i++) jin1[i]=(jin1[i-1]*K)%m1,jin2[i]=(jin2[i-1]*K)%m2;
    for(int i=1;i<=n;i++) h1[i]=(h1[i-1]*K+a[i])%m1,h2[i]=(h2[i-1]*K+a[i])%m2;
    
    manacher();
}