HDU 3294 Girls' research

题目地址

manacher

 #include<cstdio>
 #include<string.h>
 #include<algorithm>
 using namespace std;
 const int Nmax=;
 char s[Nmax];
 char str[Nmax*+];
 int p[Nmax*+];
 int hashh[Nmax*+];
 int id;
 int maxlen;
 int len;
 int start;
 int endd;
 void init()
 {
     id=;
     maxlen=;
     int n=strlen(s);
     str[]='$';
     str[]='#';
     for(int i=;i<n;i++)
     {
         str[i*+]=s[i];
         hashh[i*+]=i;
         str[i*+]='#';
     }
     str[n*+]='&';
     len=n*+;
 }

 void get()
 {
     for(int i=;i<len-;i++)
     {
         if(id+p[id]>i)
             p[i]=min(p[id*-i],p[id]+id-i);
         else
             p[i]=;
         while(str[i-p[i]] == str[i+p[i]])
             p[i]++;
         if(p[i]+i>p[id]+id)
             id=i;
         if(p[i]>maxlen)
         {
             maxlen=p[i];
             start=hashh[i-p[i]+];
             endd=hashh[i+p[i]-];
         }
     }
 }

 int main()
 {
     char c;
     while(scanf("%c",&c)!=EOF)
     {
         //printf("c:%c\n",c);
         getchar();
         scanf("%s",s);
         getchar();
         init();
         get();
         if(maxlen->=)
         {
             printf("%d %d\n",start,endd);
             for(int i=start;i<=endd;i++)
             {
                 char k=(s[i]-c+)%+'a';
                 printf("%c",k);
             }
             printf("\n");
         }
         else
             printf("No solution!\n");
     }
     return ;
 }