hdu 4333 Revolving Digits 扩展kmp

 

#include<iostream>
#include <cstdio>
#include<cstring>
using namespace std;
const int MM=201000;
int next[MM],extand[MM],next2[MM];
char S[MM],T[MM];
void GetNext(const char *T){
     int len=strlen(T),a=0;
     next[0]=len;
     while(a<len-1 && T[a]==T[a+1]) a++;
     next[1]=a;
     a=1;
     for(int k=2;k<len;k++){
         int p=a+next[a]-1,L=next[k-a];
         if( (k-1)+L >= p){
             int j = (p-k+1)>0 ? (p-k+1) : 0;
             while(k+j<len && T[k+j]==T[j]) j++;
             next[k]=j;
             a=k;
         }
         else
             next[k]=L;
     }
}
void GetExtand(const char *S,const char *T){
     GetNext(T);
     int slen=strlen(S),tlen=strlen(T),a=0;
     int MinLen = slen < tlen ? slen : tlen;
     while(a<MinLen && S[a]==T[a]) a++;
     extand[0]=a;
     a=0;
     for(int k=1;k<slen;k++){
         int p=a+extand[a]-1, L=next[k-a];
         if( (k-1)+L >= p){
             int j= (p-k+1) > 0 ? (p-k+1) : 0;
             while(k+j<slen && j<tlen && S[k+j]==T[j]) j++;
             extand[k]=j;
             a=k;
         }
         else
             extand[k]=L;
     }
}
void getNext(char T[],int len)
{
    int j,k;
    j=0;k=-1;next2[0]=-1;
    while(j<len)
    {
        if(k==-1 || T[j]==T[k])
            next2[++j]=++k;
        else k=next2[k];
    }
}

int main()
{
    int cas;
    scanf("%d",&cas);
    int now=0;
    while(cas--)
    {
        int i;
        int suml=0,sumr=0,sum=0;
        now++;
        scanf("%s",T);
        strcpy(S,T);
        strcat(S,T);
        GetExtand(S,T);
        int len=strlen(T);
        for(i=0;i<len;i++)
        {
            if(extand[i]>=len) {sum++;continue;}
            else if(T[extand[i]]>S[extand[i]+i])suml++;
            else if(T[extand[i]]<S[extand[i]+i]) sumr++;
        }
        getNext(T,len);
        int x=len-next2[len];
        int fac=1;
        if(len%x==0)fac=len/x;
        printf("Case %d: %d %d %d\n",now,suml/fac,sum/fac,sumr/fac);
    }
    return 0;
}