Suffix Automaton (SAM): Spoj lcs-longest Common Substring

Lcs-longest Common Substring No Tags

A string is finite sequence of characters over a non-empty finite setσ.

In this problem,σis the set of lowercase letters.

Substring, also called Factor, is a consecutive sequence of characters occurrences at least once in a string.

Now your task was simple, for the given strings, find the length of the longest common substring of them.

Here common substring means a substring of the or more strings.

Input

The input contains exactly the lines, each line consists of no more than 250000 lowercase letters, representing a string.

Output

The length of the longest common substring. If such string doesn ' t exist, print "0" instead.

Example

Input:alsdfkjfjkdsalfdjskalajfkdslaoutput:3

The problem is to ask for the longest common string, so I applied Sam directly.

1#include <iostream>2#include <cstdio>3#include <cstring>4 using namespacestd;5 Const intmaxn=1000010;6 structsam{7     intfa[maxn],ch[maxn][ -],len[maxn],cnt,last;8     voidInit ()9     {TenLast=cnt=1; One     } A     voidInsert (intc) -     { -         intp=last,np=last=++CNT; thelen[np]=len[p]+1; -          while(!ch[p][c]&&p) -ch[p][c]=np,p=Fa[p]; -         if(!p) fa[np]=1; +         Else{ -             intq=Ch[p][c]; +             if(len[q]==len[p]+1) Afa[np]=Q; at             Else{ -                 intnq=++cnt;len[nq]=len[p]+1; -memcpy (Ch[nq],ch[q],sizeof(Ch[p])); -fa[nq]=fa[q];fa[q]=fa[np]=NQ; -                  while(ch[p][c]==q) -ch[p][c]=nq,p=Fa[p]; in             }     -         }     to     } + }sam;  - CharSTR1[MAXN],STR2[MAXN]; the intMain () * { $     intlen1=0, len2=0, ans=0;Panax Notoginsengscanf"%s%s", STR1,STR2); - Sam. Init (); the      while(Str1[len1]) +Sam. Insert (str1[len1++]-'`'); A     intNode=1, tmp=0; the      for(; str2[len2];len2++){ +         intc=str2[len2]-'`'; -         if(Sam.ch[node][c]) $node=sam.ch[node][c],tmp++; $         Else{ -              while(node&&!Sam.ch[node][c]) -Node=Sam.fa[node]; the             if(node==0) -Node=1, tmp=0;Wuyi             Else thetmp=sam.len[node]+1, node=Sam.ch[node][c];  -         } Wuans=Max (ans,tmp); -     } Aboutprintf"%d\n", ans); $     return 0; -}

Suffix Automaton (SAM): Spoj lcs-longest Common Substring