HDU 3068 longest input string marathon Template

I wrote this question once with a suffix array a few days ago. No doubt it's very touching.-_-|

 

Today, I happened to find the marathon template. O (n) will be done in time.

Reference: http://acm.uestc.edu.cn/bbs/read.php? Tid = 3258

 

 1 #include <cstdio> 2 #include <cstring> 3 #include <iostream> 4 using namespace std; 5 #define N 110010 6 char s[N*2],str[N*2]; 7 int n,p[N*2]; 8  9 void fun()10 {11     int len=(int)strlen(s);12     str[0]=‘$‘;str[1]=‘#‘;13     n=2;14     for(int i=0;i<len;i++)15     {16         str[n++]=s[i];17         str[n++]=‘#‘;18     }19     str[n]=‘\0‘;20 }21 22 void Manacher()23 {24     int i,id,mx=0;25     for(i=1;i<n;i++)26     {27         if(mx > i)28             p[i]=min(p[2*id-i],p[id]+id-i);29         else30             p[i]=1;31         for(;str[i+p[i]] == str[i-p[i]];p[i]++)32             ;33         if(p[i]+i > mx)34         {35             mx=p[i]+i;36             id=i;37         }38     }39 }40 41 void work()42 {43     int ans=-1;44     for(int i=1;i<n;i++)45         ans=max(ans,p[i]);46     printf("%d\n",ans-1);47 }48 49 int main()50 {51     while(scanf("%s",s)!=EOF)52     {53         fun();54         Manacher();55         work();56     }57     return 0;58 }

 

HDU 3068 longest input string marathon Template