HDU 3294 Manacher模版题

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long ll;
const int inf=0x3f3f3f3f;
const int maxn=200010;
char str[maxn],tmp[maxn<<1];
int len1[maxn<<1],pos;
int init(char *st){
int len=strlen(st);
tmp[0]='@';
for(int i=1;i<=2*len;i+=2){
tmp[i]='#';
tmp[i+1]=st[i/2];
}
tmp[2*len+1]='#';
tmp[2*len+2]='$';
tmp[2*len+3]=0;
return 2*len+1;
}
int Manacher(char *st,int len){
int p=0,ans=0,po=0;
for(int i=1;i<=len;i++){
if(p>i) len1[i]=min(p-i,len1[2*po-i]);
else len1[i]=1;
while(st[i-len1[i]]==st[i+len1[i]]) len1[i]++;
if(len1[i]+i>p){
p=len1[i]+i;
po=i;
}
if(len1[i]>ans){
ans=len1[i];
pos=i;
}
}
return ans-1;
}
int main(){
char ch;
while(scanf(" %c%s",&ch,str)!=-1){
init(str);
int len=init(str);
int ans=Manacher(tmp,len);
if(ans==1) printf("No solution!\n");
else{
int le,ri;
if(pos%2==0){
le=pos/2-1-ans/2;
ri=le+ans-1;
}else{
le=pos/2-ans/2;
ri=le+ans-1;
}
printf("%d %d\n",le,ri);
int t=ch-'a';
for(int i=le;i<=ri;i++){
int k=str[i]-t;
if(k>=97) printf("%c",str[i]-t);
else printf("%c",str[i]-t+26);
}
printf("\n");
}
}
return 0;
}