제출 #262065

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
262065		mohamedsobhi777	회문 (APIO14_palindrome)	C++14	0 / 100	26 ms	26248 KiB

palindrome

//#include "elephants.h"
#include<bits/stdc++.h>

#define I inline void 

using namespace std ; 

using ld = long double ; 
using ll = long long ; 

const int N = 1e5  + 7 , mod = 1e9 + 7 ; 

int n;
ll ans ; 
string s;
int num , suf ; 

struct node{
	int nxt[26] ; 
	int len ; 
	int num ; 
	int occ ; 
	int lazy ; 
	int suflnk ; 
} tree[N] ; 


bool addL(int pos){
	int cur = suf , curlen = 0 ; 
	int let = s[pos] - 'a' ; 

	while(1){
		curlen = tree[cur].len ;
		if(pos - 1 - curlen >=0 && s[pos - 1 - curlen ] == s[pos])
			break ; 
		cur = tree[cur].suflnk ;
	}

	if(tree[cur].nxt[let]){
		suf = tree[cur].nxt[let] ; 
		tree[suf].lazy++ ; 
		return 0 ; 
	}

	num ++ ;
	suf = num ;
	tree[num].len = tree[cur].len + 2 ; 
	
	tree[cur].nxt[let] = num ;

	tree[num].lazy ++ ;  

	if(tree[num].len == 1){
		tree[num].suflnk = 2 ; 
		tree[num].lazy = 1; 
		return 1 ; 
	}

	while(1){
		cur = tree[cur].suflnk ; 
		curlen = tree[cur].len ; 
		if(pos -1 - curlen >= 0 && s[pos] == s[pos - 1 - curlen ]){
			tree[num].suflnk = tree[cur].nxt[let] ; 
			break ;
		}
	}

	tree[num].num = 1 + tree[tree[num].suflnk].num ; 

	return 1 ; 
}

I init(){
	suf = num = 2 ; 
	tree[1].len = -1 ; 
	tree[2].len = 0 ; 
	tree[1].suflnk = 1 ; 
	tree[2].suflnk = 1 ; 
}

int pal[N] ; 
int vis[N] ; 

int main(){

	ios_base::sync_with_stdio(0) ; 
	cin.tie(0) ; 
	//freopen("in.in" , "r" , stdin) ; 
	init() ; 
	cin >> s ; 
	n = (int) s.size() ; 
	for(int i = 0 ;i < n ;i++){
		addL(i) ; 
		ans+= tree[suf].num ; 
	}	

	for(int i = num ;i > 2 ;i--){
		int cur = i ; 
		int lz = tree[cur].lazy ; 
		while(cur > 2 && !vis[cur]++ ){		
			vis[cur] = 1; 
			pal[cur]+= lz ; 
			lz+=tree[cur].lazy ; 
			cur = tree[cur].suflnk ;

		}
	}

	for(int i = 3 ;i <= num ;i++){
		ans = max(ans , 1ll * tree[i].len * pal[i] ) ; 
	}

	cout<< ans << endl; 
	return 0 ; 
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 26
• Subtask 5: 0 / 27