1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 using namespace std; 6 const int N=2e6+440; 7 char str1[N],str[N<<1]; 8 int rad[N]; 9 char temp;10 void Manacher(int *rad,char *str,int n){11    int i,mx=0,id;12    for(int i=1;i<n;i++){13     if(mx>i){14     rad[i]=min(rad[2*id-i],mx-i);15    }16    else17     rad[i]=1;18     for(;str[i-rad[i]]==str[i+rad[i]];rad[i]++){19         if(rad[i]+i>mx){20             mx=rad[i]+i;21             id=i;22         }23      }24    }25 }26 27 int main(){28     int cas=1;29   while(~scanf("%s",str1)){30        if(str1[0]==‘E‘)break;31       int nn=strlen(str1);32         int n=2*nn+2;33         str[0]=‘$‘;34       for(int i=0;i<=nn;i++){35           str[2*i+1]=‘#‘;36           str[2*i+2]=str1[i];37       }38       memset(rad,0,sizeof(rad));39       Manacher(rad,str,n);40       int ans=0;41       for(int i=0;i<=n;i++){42         if(rad[i]>=3&&rad[i]>ans){43             ans=rad[i];44         }45       }46       printf("Case %d: %d\n",cas++,ans-1);47   }48 }