Submission #366347

#	Time	Username	Problem	Language	Result	Execution time	Memory
366347		YJU	Palindromes (APIO14_palindrome)	C++14	0 / 100	81 ms	78324 KiB

palindrome

#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector,Ofast")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
const ll MOD=1e9+7;
const ll MOD2=998244353;
const ll N=1e6+5;
const ld pi=acos(-1);
const ll INF=(1LL<<60);
#define SQ(i) ((i)*(i))
#define REP(i,n) for(ll i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define setp setprecision
#define lwb lower_bound
#define SZ(_a) (ll)_a.size()

struct node{
	ll length,start,end,cnt;
	ll insert_edge[26];
	ll suffix_edge;
};

node tree[N];
string s;
ll ptr,cur;
ll vis[N];

void insert(ll id){
	ll tmp=cur;
	while(1){
		if(id-tree[tmp].length>=1&&s[id]==s[id-tree[tmp].length-1])break;
		tmp=tree[tmp].suffix_edge;
	}
	if(tree[tmp].insert_edge[s[id]-'a']!=0){
		cur=tree[tmp].insert_edge[s[id]-'a'];
		++tree[tmp].cnt;
		return ;
	}
	
	//build new node
	
	++ptr;
	tree[tmp].insert_edge[s[id]-'a']=ptr;
	tree[ptr].length=tree[tmp].length+2;
	tree[ptr].end=id;
	tree[ptr].start=id-tree[ptr].length+1;
	tree[ptr].cnt=1;
	
	// suffix_edge
	
	tmp=tree[tmp].suffix_edge;
	cur=ptr;
	if(tree[cur].length==1){
		tree[cur].suffix_edge=2;
		return; 
	}
	while(1){
		if(id-tree[tmp].length>=1&&s[id]==s[id-tree[tmp].length-1])break;
		tmp=tree[tmp].suffix_edge;
	}
	tree[cur].suffix_edge=tree[tmp].insert_edge[s[id]-'a'];
}

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
	tree[1].length=-1;
	tree[1].suffix_edge=1;
	tree[2].length=0;
	tree[2].suffix_edge=1;
	ptr=2;
	cur=1;
	cin>>s;
	REP(i,SZ(s))insert(i);
	
	stack<ll> stk;
	queue<ll> que;
	stk.push(1);stk.push(2);que.push(1);que.push(2);
	vis[1]=vis[2]=1;
	while(SZ(que)){
		ll x=que.front();que.pop();
		REP(i,26){
			ll y=tree[x].insert_edge[i];
			if(y!=0&&!vis[y]){
				stk.push(y);que.push(y);vis[y]=1;
			}
		}
	}
	while(SZ(stk)){
		ll x=stk.top();stk.pop();
		tree[tree[x].suffix_edge].cnt+=tree[x].cnt;
	}
	ll ans=0;
	for(int i=3;i<=ptr;i++)ans=max(ans,tree[i].length*tree[i].cnt);
	cout<<ans<<"\n";
	return 0;
}

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