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Submission #168093

# Submission time Handle Problem Language Result Execution time Memory
168093 2019-12-11T11:01:06 Z HungAnhGoldIBO2020 Palindromes (APIO14_palindrome) C++14
73 / 100
 1000 ms 113744 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 int long long
#define hash hash2
using namespace std;
const int N=3e5+4;
const int mod=1e9+9;
const int base=211;
const int mod1=1610612741;
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};
}
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<int,int> 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:60:15: 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 376 KB Output is correct
2 Correct 2 ms 376 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 376 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 380 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 504 KB Output is correct
21 Correct 2 ms 504 KB Output is correct
22 Correct 2 ms 504 KB Output is correct
23 Correct 2 ms 376 KB Output is correct
24 Correct 2 ms 504 KB Output is correct
25 Correct 2 ms 376 KB Output is correct
26 Correct 2 ms 380 KB Output is correct
27 Correct 2 ms 376 KB Output is correct
28 Correct 2 ms 376 KB Output is correct
29 Correct 2 ms 428 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 504 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 760 KB Output is correct
2 Correct 3 ms 760 KB Output is correct
3 Correct 3 ms 760 KB Output is correct
4 Correct 3 ms 760 KB Output is correct
5 Correct 3 ms 760 KB Output is correct
6 Correct 3 ms 760 KB Output is correct
7 Correct 3 ms 760 KB Output is correct
8 Correct 3 ms 760 KB Output is correct
9 Correct 3 ms 632 KB Output is correct
10 Correct 2 ms 504 KB Output is correct
11 Correct 2 ms 508 KB Output is correct
12 Correct 2 ms 632 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 4088 KB Output is correct
2 Correct 13 ms 4088 KB Output is correct
3 Correct 17 ms 4216 KB Output is correct
4 Correct 16 ms 4088 KB Output is correct
5 Correct 10 ms 4088 KB Output is correct
6 Correct 11 ms 3960 KB Output is correct
7 Correct 13 ms 3832 KB Output is correct
8 Correct 4 ms 1016 KB Output is correct
9 Correct 4 ms 1016 KB Output is correct
10 Correct 8 ms 3064 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 235 ms 38168 KB Output is correct
2 Correct 191 ms 36580 KB Output is correct
3 Correct 254 ms 38112 KB Output is correct
4 Correct 238 ms 36724 KB Output is correct
5 Correct 135 ms 36956 KB Output is correct
6 Correct 99 ms 27640 KB Output is correct
7 Correct 180 ms 30564 KB Output is correct
8 Correct 29 ms 5624 KB Output is correct
9 Correct 66 ms 12920 KB Output is correct
10 Correct 104 ms 32376 KB Output is correct

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 721 ms 113684 KB Output is correct
2 Correct 677 ms 105364 KB Output is correct
3 Execution timed out 1084 ms 113744 KB Time limit exceeded
4 Halted 0 ms 0 KB -