// ~ Be Name Khoda ~
#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast")
#pragma GCC target("avx2")
#pragma GCC optimize("unroll-loops")
using namespace std;
typedef long long ll;
#define all(x) x.begin(), x.end()
#define pb push_back
#define fi first
#define se second
const int maxn5 = 3e5 + 10;
const int lg = 19;
const ll inf = 1e18;
const int al = 200;
int rnk[lg][maxn5], a[maxn5], lef[maxn5], rig[maxn5];
int val[maxn5], mn[maxn5], lcp[maxn5], rev[maxn5];
int cmpid, lenlen, cmpsz, z[2][maxn5];
set <int> av[2];
vector <int> srt[maxn5];
vector <pair<int, int>> ed;
vector <pair<int, pair<int, int>>> have;
vector <pair<pair<int, int>, int>> req;
inline int get_lcp(int v, int u){
int ans = 0;
for(int i = lg - 1; i >= 0; i--) if(rnk[i][u] == rnk[i][v]){
u += (1 << i);
v += (1 << i);
ans += (1 << i);
}
return ans;
}
inline void fix2(int& a){
if(a < 0)
a += cmpsz;
if(a >= cmpsz)
a -= cmpsz;
}
inline int fix(int a){
if(a >= cmpsz)
a -= cmpsz;
return a;
}
inline bool cmp(int i, int j){
return rnk[cmpid][i] < rnk[cmpid][j] || (rnk[cmpid][i] == rnk[cmpid][j] && rnk[cmpid][fix(i + lenlen)] < rnk[cmpid][fix(j + lenlen)]);
}
inline void sort1(int n){
for(int i = 0; i < max(n, al); i++)
srt[i].clear();
for(int i = 0; i < n; i++)
srt[rnk[cmpid][fix(i + lenlen)]].pb(i);
int pt = 0;
for(int i = 0; i < max(n, al); i++)
for(auto u : srt[i])
a[pt++] = u;
}
inline void sort(){
int n = cmpsz;
for(int i = 0; i < n; i++)
srt[rnk[cmpid][a[i]]].pb(a[i]);
int pt = 0;
for(int i = 0; i < max(n, al); i++){
for(auto u : srt[i])
a[pt++] = u;
srt[i].clear();
}
}
inline void build_sf(string s){
s.pb('#');
int n = cmpsz = s.size();
for(int i = 0; i < n; i++){
rnk[0][i] = int(s[i]);
srt[rnk[0][i]].pb(i);
}
int pt = 0;
for(int i = 0; i < al; i++) for(auto u : srt[i])
a[pt++] = u;
for(int i = 0; i < al; i++)
srt[i].clear();
for(int j = 1; j < lg; j++){
cmpid = j - 1; lenlen = (1 << cmpid) % n;
for(int i = 0; i < n; i++)
fix2(a[i] = a[i] - lenlen);
sort();
rnk[j][a[0]] = 0;
for(int i = 1; i < n; i++){
rnk[j][a[i]] = rnk[j][a[i - 1]] + cmp(a[i - 1], a[i]);
}
}
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
string s; cin >> s;
int n = s.size();
build_sf(s);
for(int i = 0; i < n; i++)
a[i] = a[i + 1];
for(int i = 1; i < n; i++){
lcp[i] = get_lcp(a[i - 1], a[i]);
ed.pb({lcp[i], i});
}
ll ans = 0;
//cout << t << endl;
for(int i = 0; i < n; i++){
//cout << a[i] << ' ';
rev[a[i]] = i;
lef[i] = rig[i] = i;
}
int l = 0, r = 0;
for(int i = 0; i < n; i++){
if(i){
if(r >= i)
z[1][i] = min(r - i + 1, z[1][r + l - i + 1]);
while(z[1][i] + i < n && i - z[1][i] - 1 >= 0 && s[i + z[1][i]] == s[i - z[1][i] - 1])
z[1][i]++;
have.pb({i - z[1][i], {1, i - 1}});
ans = max(ans, z[1][i] * 2LL);
if(i + z[1][i] - 1 > r){
r = i + z[1][i] - 1;
l = i - z[1][i];
}
}
if(r >= i)
z[0][i] = min(r - i + 1, z[0][r + l - i]);
while(z[0][i] + i < n && i - z[0][i] >= 0 && s[i + z[0][i]] == s[i - z[0][i]])
z[0][i]++;
have.pb({i - z[0][i] + 1, {0, i}});
if(i + z[0][i] - 1 > r){
r = i + z[0][i] - 1;
l = i - z[0][i] + 1;
}
ans = max(ans, z[0][i] * 2LL - 1);
}
sort(all(ed));
while(ed.size()){
int id = ed.back().se, len = ed.back().fi;
ed.pop_back();
int l, r;
lef[rig[id]] = l = lef[id - 1];
rig[lef[id - 1]] = r = rig[id];
req.pb({{a[l], len}, r - l + 1});
}
sort(all(req));
sort(all(have));
int ind = 0;
//cout << "having " << ans << endl;
for(auto [b, val] : req){
int l = b.fi, len = b.se;
//cout << "A request of " << l << ' ' << len << ' ' << val << endl;
while(ind < have.size() && have[ind].fi <= l){
av[have[ind].se.fi].insert(have[ind].se.se);
//cout << "adding " << have[ind].fi << ' ' << have[ind].se.fi << ' ' << have[ind].se.se << endl;
ind++;
}
int klen = len / 2;
int slen = klen + len % 2;
auto it = av[0].upper_bound(l + slen - 1);
if(av[0].size() && it != av[0].begin()){
it--;
ans = max(ans, ll(val) * (((*it) - l) * 2 + 1));
//cout << "well fard " << (*it) << ' ' << ans << endl;
}
it = av[1].upper_bound(l + klen - 1);
if(av[1].size() && it != av[1].begin()){
it--;
ans = max(ans, ll(val) * ((*it) - l + 1) * 2);
//cout << "well zoj " << (*it) << ' ' << ans << endl;
}
}
cout << ans << endl;
}
/*
Why so fast...?
Hold on...
Hold your breath...
Need anything else?
Nein, Kein Problem...
Das Leben war schon immer so grausam :)
*/
Compilation message
palindrome.cpp: In function 'int main()':
palindrome.cpp:173:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
173 | while(ind < have.size() && have[ind].fi <= l){
| ~~~~^~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
7508 KB |
Output is correct |
2 |
Correct |
4 ms |
7508 KB |
Output is correct |
3 |
Correct |
4 ms |
7508 KB |
Output is correct |
4 |
Correct |
3 ms |
7508 KB |
Output is correct |
5 |
Correct |
4 ms |
7508 KB |
Output is correct |
6 |
Correct |
4 ms |
7508 KB |
Output is correct |
7 |
Correct |
4 ms |
7508 KB |
Output is correct |
8 |
Correct |
3 ms |
7508 KB |
Output is correct |
9 |
Correct |
3 ms |
7508 KB |
Output is correct |
10 |
Correct |
4 ms |
7508 KB |
Output is correct |
11 |
Correct |
4 ms |
7508 KB |
Output is correct |
12 |
Correct |
4 ms |
7508 KB |
Output is correct |
13 |
Correct |
4 ms |
7508 KB |
Output is correct |
14 |
Correct |
4 ms |
7508 KB |
Output is correct |
15 |
Correct |
4 ms |
7508 KB |
Output is correct |
16 |
Correct |
4 ms |
7508 KB |
Output is correct |
17 |
Correct |
4 ms |
7508 KB |
Output is correct |
18 |
Correct |
3 ms |
7508 KB |
Output is correct |
19 |
Correct |
4 ms |
7508 KB |
Output is correct |
20 |
Correct |
4 ms |
7508 KB |
Output is correct |
21 |
Correct |
4 ms |
7508 KB |
Output is correct |
22 |
Correct |
3 ms |
7508 KB |
Output is correct |
23 |
Correct |
4 ms |
7508 KB |
Output is correct |
24 |
Correct |
4 ms |
7508 KB |
Output is correct |
25 |
Correct |
4 ms |
7508 KB |
Output is correct |
26 |
Correct |
4 ms |
7508 KB |
Output is correct |
27 |
Correct |
4 ms |
7664 KB |
Output is correct |
28 |
Correct |
5 ms |
7508 KB |
Output is correct |
29 |
Correct |
4 ms |
7508 KB |
Output is correct |
30 |
Correct |
4 ms |
7508 KB |
Output is correct |
31 |
Correct |
4 ms |
7508 KB |
Output is correct |
32 |
Correct |
4 ms |
7508 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
7764 KB |
Output is correct |
2 |
Correct |
5 ms |
7764 KB |
Output is correct |
3 |
Correct |
4 ms |
7764 KB |
Output is correct |
4 |
Correct |
5 ms |
7764 KB |
Output is correct |
5 |
Correct |
5 ms |
7764 KB |
Output is correct |
6 |
Correct |
5 ms |
7764 KB |
Output is correct |
7 |
Correct |
5 ms |
7764 KB |
Output is correct |
8 |
Correct |
4 ms |
7764 KB |
Output is correct |
9 |
Correct |
5 ms |
7764 KB |
Output is correct |
10 |
Correct |
5 ms |
7764 KB |
Output is correct |
11 |
Correct |
5 ms |
7764 KB |
Output is correct |
12 |
Correct |
5 ms |
7764 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
13 ms |
10856 KB |
Output is correct |
2 |
Correct |
13 ms |
10512 KB |
Output is correct |
3 |
Correct |
14 ms |
10776 KB |
Output is correct |
4 |
Correct |
13 ms |
10712 KB |
Output is correct |
5 |
Correct |
17 ms |
10588 KB |
Output is correct |
6 |
Correct |
15 ms |
10564 KB |
Output is correct |
7 |
Correct |
13 ms |
10544 KB |
Output is correct |
8 |
Correct |
17 ms |
10268 KB |
Output is correct |
9 |
Correct |
16 ms |
10332 KB |
Output is correct |
10 |
Correct |
15 ms |
10448 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
120 ms |
40848 KB |
Output is correct |
2 |
Correct |
118 ms |
39240 KB |
Output is correct |
3 |
Correct |
118 ms |
40744 KB |
Output is correct |
4 |
Correct |
118 ms |
40452 KB |
Output is correct |
5 |
Correct |
141 ms |
38952 KB |
Output is correct |
6 |
Correct |
142 ms |
40148 KB |
Output is correct |
7 |
Correct |
128 ms |
39676 KB |
Output is correct |
8 |
Correct |
204 ms |
35628 KB |
Output is correct |
9 |
Correct |
174 ms |
36576 KB |
Output is correct |
10 |
Correct |
152 ms |
39216 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
375 ms |
94756 KB |
Output is correct |
2 |
Correct |
367 ms |
106924 KB |
Output is correct |
3 |
Correct |
381 ms |
103616 KB |
Output is correct |
4 |
Correct |
370 ms |
104124 KB |
Output is correct |
5 |
Correct |
488 ms |
107252 KB |
Output is correct |
6 |
Correct |
430 ms |
104248 KB |
Output is correct |
7 |
Correct |
453 ms |
103616 KB |
Output is correct |
8 |
Correct |
958 ms |
91552 KB |
Output is correct |
9 |
Correct |
965 ms |
91484 KB |
Output is correct |
10 |
Correct |
570 ms |
101892 KB |
Output is correct |
11 |
Correct |
355 ms |
100496 KB |
Output is correct |
12 |
Correct |
877 ms |
92864 KB |
Output is correct |