Palindrome Tree (count all palindrome strings)-Mccme 1750подпалиндромы

подпалиндромы

problem ' s Link: http://informatics.mccme.ru//mod/statements/view.php?chapterid=1750#

 

Mean:

Give you a string of not more than 1e5 length, to count the total number of palindrome string. (The first Russian question, fortunately there is Google translation).

Analyse:

If the topic is said to be different palindrome string, the problem is a bare palindrome tree.

Because of the number of palindrome required for all substrings, we also need to use Suffixlink to go up the statistical answer when inserting.

Time complexity:o (N)

 

Source code:

/*
* This code was made by Crazyacking
* verdict:accepted
* Submission date:2015-08-17-19.13
* time:0ms
* memory:137kb
*/
#include <queue>
#include <cstdio>
#include <set>
#include <string>
#include <stack>
#include <cmath>
#include <climits>
#include <map>
#include <cstdlib>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#define LL Long Long
#define ULL unsigned long long
using namespace STD;

Const int MAXN = 105000;
struct node
{
int Next[ -];
int Len;
int Sufflink;
int Num;
};
int Len;
CharS[MAXN];
node Tree[MAXN];
int Num;//Node 1-root with len-1, node 2-root with Len 0
int Suff;//MAX suffix palindrome
Long Long ans;
BOOL Addletter(int POS)
{
int cur = Suff, Curlen = 0;
int Let =S[POS] - ' A ';
while(true)
{
Curlen = Tree[cur].Len;
if(POS-1-Curlen>=0&&S[POS-1-Curlen]==S[POS]) Break;
cur = Tree[cur].Sufflink;
}
if(Tree[cur].Next[ Let])
{
Suff = Tree[cur].Next[ Let];
return false;
} Suff = ++Num;
Tree[Num].Len = Tree[cur].Len + 2;
Tree[cur].Next[ Let] = Num;
if(Tree[Num].Len == 1)
{
Tree[Num].Sufflink = 2;
Tree[Num].Num = 1;
return true;
}
while(true)
{
cur = Tree[cur].Sufflink;
Curlen = Tree[cur].Len;
if(POS - 1 - Curlen >= 0 &&S[POS - 1 - Curlen] ==S[POS])
{
Tree[Num].Sufflink = Tree[cur].Next[ Let];
Break;
}
}
Tree[Num].Num = 1 + Tree[Tree[Num].Sufflink].Num;
return true;
}
void Inittree()
{
Num = 2;Suff = 2;
Tree[1].Len = -1;Tree[1].Sufflink = 1;
Tree[2].Len = 0;Tree[2].Sufflink = 1;
}
int Main()
{
gets(s);
Inittree();
for(int I = 0; s[I]; I++)
{
Addletter(I);
ans += Tree[Suff].Num;
} cout << ans << Endl;
return 0;
}

Palindrome Tree (count all palindrome strings)-Mccme 1750подпалиндромы