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Submission #168099

# Submission time Handle Problem Language Result Execution time Memory
168099 2019-12-11T11:09:37 Z HungAnhGoldIBO2020 Palindromes (APIO14_palindrome) C++14
100 / 100
 942 ms 81196 KB 
/*
abacaba
*/
#include<bits/stdc++.h>
#pragma GCC optimize("Ofast,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#define hash hash2
using namespace std;
const int N=3e5+4;
const int mod=1e9+9;
const int base=1e9+7;
const int mod1=1610612741;
#define int long long
int hash[N],rev_hash[N],mul[N],max1=1,sum[N],mul1[N],hash1[N],rev_hash1[N];
map<pair<int,int>,int> cnt;
pair<int,int> gethash(int l,int r){
	return {((hash[r]-hash[l-1]*mul[r-l+1])%mod+mod)%mod,((hash1[r]-hash1[l-1]*mul1[r-l+1])%mod1+mod1)%mod1};
}
pair<int,int> gethash_rev(int l,int r){
	return {((rev_hash[l]-rev_hash[r+1]*mul[r-l+1])%mod+mod)%mod,((rev_hash1[l]-rev_hash1[r+1]*mul1[r-l+1])%mod1+mod1)%mod1};
}
#undef int
struct node{
	int nxt[26],len,suf;
};
node Eer[N];
int sz=0,lst;
string s;
void add(int idx){
//	cout<<idx<<" BEGIN"<<endl;
	int cha=(s[idx]-'a');
	while(idx-Eer[lst].len-1<0||s[idx]!=s[idx-Eer[lst].len-1]){
		lst=Eer[lst].suf;
	}
	if(!Eer[lst].nxt[cha]){
		sz++;
		Eer[lst].nxt[cha]=sz;
		Eer[sz].len=Eer[lst].len+2;
		if(Eer[sz].len!=1){
			int sf=Eer[lst].suf;
			while(idx-Eer[sf].len-1<0||s[idx]!=s[idx-Eer[sf].len-1]){
				sf=Eer[sf].suf;
			}
			Eer[sz].suf=Eer[sf].nxt[cha];
		}
		else{
			Eer[sz].suf=2;
		}
	}
	lst=Eer[lst].nxt[cha];
	return;
}
void build(string s1){
	sz=2;
	Eer[1].len=-1;
	Eer[1].suf=0;
	Eer[2].len=0;
	Eer[2].suf=1;
	lst=2;
	s=s1;
	for(int i=0;i<s.size();i++){
		add(i);
	}
}
void dfs(int x,pair<long long,long long> val){
	sum[x]=cnt[val];
	for(int i=0;i<26;i++){
		if(Eer[x].nxt[i]){
			if(x==1){
				dfs(Eer[x].nxt[i],{i+1,i+1});
			}
			else{
				dfs(Eer[x].nxt[i],{(i+1+val.first*base+(i+1)*mul[Eer[x].len+1])%mod,(i+1 + val.second*base + (i+1)*mul1[Eer[x].len+1])%mod1});
			}
			sum[x]+=sum[Eer[x].nxt[i]];
		}
	}
	max1=max(max1,Eer[x].len * sum[x]);
}
signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	string s1;
	cin>>s1;
	build(s1);
	int n=s1.size(),i,j,k,l;
	s1=" "+s1;
	mul[0]=1;
	mul1[0]=1;
	for(i=1;i<=n;i++){
		hash[i]=(hash[i-1]*base+(s1[i]-'a'+1))%mod;
		mul[i]=(mul[i-1]*base)%mod;
		hash1[i]=(hash1[i-1]*base+(s1[i]-'a'+1))%mod1;
		mul1[i]=(mul1[i-1]*base)%mod1;
	}
	for(i=n;i>0;i--){
		rev_hash[i]=(rev_hash[i+1]*base+(s1[i]-'a'+1))%mod;
		rev_hash1[i]=(rev_hash1[i+1]*base+(s1[i]-'a'+1))%mod1;
	}
	for(i=1;i<=n;i++){
		k=0;
		l=min(i-1,n-i);
		while(k<l){
			j=(k+l+1)>>1;
			if(gethash(i-j,i+j)==gethash_rev(i-j,i+j)){
				k=j;
			}
			else{
				l=j-1;
			}
		}
		cnt[gethash(i-k,i+k)]++;
		if(i<=n&&s1[i]==s1[i+1]){
			k=0;
			l=min(i-1,n-i-1);
			while(k<l){
				j=(k+l+1)>>1;
				if(gethash(i-j,i+1+j)==gethash_rev(i-j,i+1+j)){
					k=j;
				}
				else{
					l=j-1;
				}
			}
			cnt[gethash(i-k,i+1+k)]++;
		}
	}
	dfs(1,{0,0});
	dfs(2,{0,0});
	cout<<max1;
}

Compilation message

palindrome.cpp: In function 'void build(std::__cxx11::string)':
palindrome.cpp:61:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.size();i++){
              ~^~~~~~~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Correct 2 ms 380 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 380 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 376 KB Output is correct
13 Correct 2 ms 376 KB Output is correct
14 Correct 2 ms 376 KB Output is correct
15 Correct 2 ms 376 KB Output is correct
16 Correct 2 ms 376 KB Output is correct
17 Correct 2 ms 376 KB Output is correct
18 Correct 2 ms 376 KB Output is correct
19 Correct 2 ms 376 KB Output is correct
20 Correct 2 ms 380 KB Output is correct
21 Correct 2 ms 376 KB Output is correct
22 Correct 2 ms 376 KB Output is correct
23 Correct 2 ms 504 KB Output is correct
24 Correct 2 ms 504 KB Output is correct
25 Correct 2 ms 504 KB Output is correct
26 Correct 2 ms 508 KB Output is correct
27 Correct 2 ms 508 KB Output is correct
28 Correct 2 ms 508 KB Output is correct
29 Correct 2 ms 504 KB Output is correct
30 Correct 2 ms 376 KB Output is correct
31 Correct 2 ms 376 KB Output is correct
32 Correct 2 ms 376 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 632 KB Output is correct
2 Correct 3 ms 632 KB Output is correct
3 Correct 3 ms 632 KB Output is correct
4 Correct 3 ms 632 KB Output is correct
5 Correct 3 ms 632 KB Output is correct
6 Correct 3 ms 680 KB Output is correct
7 Correct 3 ms 632 KB Output is correct
8 Correct 3 ms 636 KB Output is correct
9 Correct 3 ms 632 KB Output is correct
10 Correct 3 ms 504 KB Output is correct
11 Correct 2 ms 504 KB Output is correct
12 Correct 3 ms 632 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 3064 KB Output is correct
2 Correct 11 ms 3064 KB Output is correct
3 Correct 16 ms 3064 KB Output is correct
4 Correct 15 ms 3064 KB Output is correct
5 Correct 9 ms 2936 KB Output is correct
6 Correct 10 ms 2936 KB Output is correct
7 Correct 12 ms 2780 KB Output is correct
8 Correct 4 ms 888 KB Output is correct
9 Correct 4 ms 1016 KB Output is correct
10 Correct 8 ms 2300 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 164 ms 27152 KB Output is correct
2 Correct 168 ms 25532 KB Output is correct
3 Correct 248 ms 27276 KB Output is correct
4 Correct 210 ms 25872 KB Output is correct
5 Correct 97 ms 25948 KB Output is correct
6 Correct 88 ms 19624 KB Output is correct
7 Correct 143 ms 21244 KB Output is correct
8 Correct 32 ms 5496 KB Output is correct
9 Correct 64 ms 10360 KB Output is correct
10 Correct 99 ms 23112 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 660 ms 80884 KB Output is correct
2 Correct 599 ms 72488 KB Output is correct
3 Correct 942 ms 80928 KB Output is correct
4 Correct 888 ms 73776 KB Output is correct
5 Correct 403 ms 79532 KB Output is correct
6 Correct 559 ms 66220 KB Output is correct
7 Correct 602 ms 62668 KB Output is correct
8 Correct 110 ms 15664 KB Output is correct
9 Correct 107 ms 15664 KB Output is correct
10 Correct 364 ms 69812 KB Output is correct
11 Correct 527 ms 81196 KB Output is correct
12 Correct 150 ms 21552 KB Output is correct