#pragma GCC optimize ("Ofast")
#pragma GCC target ("avx2")
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.h>
#else
#define debug(...)
#endif
#define ft front
#define bk back
#define st first
#define nd second
#define ins insert
#define ers erase
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define bg begin
#define ed end
#define all(x) (x).bg(), (x).ed()
#define sz(x) (int)(x).size()
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
template<typename T> T gcd(T a, T b) { return (b == 0? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
#define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
#define FRN(i, n) for (int (i) = 0; (i) < (n); ++(i))
#define FSN(i, n) for (int (i) = (n) - 1; (i) >= 0; --(i))
#define EACH(i, x) for (auto &(i) : (x))
#define WHILE while
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
----------------------------------------------------------------
END OF TEMPLATE
----------------------------------------------------------------
Tran The Bao - ghostwriter
Training for VOI23 gold medal
----------------------------------------------------------------
DIT ME CHUYEN BAO LOC
----------------------------------------------------------------
*/
const pi M = {1e9 + 7, 1e9 + 9};
const pi base = {37, 127};
const int N = 3e5 + 5;
int n, d[N];
str s;
pi p[N], h[N], h1[N];
vpi v, v1, v2;
map<pi, bool> d1;
ll rs = 0;
pi geth(const int &l, const int &r) {
pi ans;
ans.st = (h[r].st - 1LL * h[l - 1].st * p[r - l + 1].st % M.st + M.st) % M.st;
ans.nd = (h[r].nd - 1LL * h[l - 1].nd * p[r - l + 1].nd % M.nd + M.nd) % M.nd;
return ans;
}
pi geth1(const int &l, const int &r) {
pi ans;
ans.st = (h1[l].st - 1LL * h1[r + 1].st * p[r - l + 1].st % M.st + M.st) % M.st;
ans.nd = (h1[l].nd - 1LL * h1[r + 1].nd * p[r - l + 1].nd % M.nd + M.nd) % M.nd;
return ans;
}
bool cmp(const pi &a, const pi &b) { return a.nd - a.st + 1 < b.nd - b.st + 1; }
int getpos(const pi &x) { if (x > v1.bk()) return -1; int ans = lb(all(v1), x) - v1.bg(); return x == v1[ans]? ans : -1; }
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
// freopen(file".inp", "r", stdin);
// freopen(file".out", "w", stdout);
p[0] = {1, 1};
FOR(i, 1, N - 1) {
p[i].st = 1LL * p[i - 1].st * base.st % M.st;
p[i].nd = 1LL * p[i - 1].nd * base.nd % M.nd;
}
cin >> s;
n = sz(s);
s = "#" + s + "#";
FOR(i, 1, n) {
h[i].st = (1LL * h[i - 1].st * base.st % M.st + s[i] - 'a' + 1) % M.st;
h[i].nd = (1LL * h[i - 1].nd * base.nd % M.nd + s[i] - 'a' + 1) % M.nd;
}
FOS(i, n, 1) {
h1[i].st = (1LL * h1[i + 1].st * base.st % M.st + s[i] - 'a' + 1) % M.st;
h1[i].nd = (1LL * h1[i + 1].nd * base.nd % M.nd + s[i] - 'a' + 1) % M.nd;
}
FOR(i, 1, n) {
int l = 1, r = min(i - 1, n - i), ans = 0;
WHILE(l <= r) {
int mid = l + (r - l) / 2;
if (geth(i - mid, i + mid) == geth1(i - mid, i + mid)) {
ans = mid;
l = mid + 1;
}
else r = mid - 1;
}
l = i - ans;
r = i + ans;
pi curh = geth(l, r);
v2.pb(curh);
WHILE(!d1[curh]) {
v.pb({l, r});
d1[curh] = 1;
++l;
--r;
if (l > r) break;
curh = geth(l, r);
}
}
FOR(i, 1, n - 1) {
if (s[i] != s[i + 1]) continue;
int l = 1, r = min(i - 1, n - i - 1), ans = 0;
WHILE(l <= r) {
int mid = l + (r - l) / 2;
if (geth(i - mid, i + 1 + mid) == geth1(i - mid, i + 1 + mid)) {
ans = mid;
l = mid + 1;
}
else r = mid - 1;
}
l = i - ans;
r = i + 1 + ans;
pi curh = geth(l, r);
v2.pb(curh);
WHILE(!d1[curh]) {
v.pb({l, r});
d1[curh] = 1;
++l;
--r;
if (l > r) break;
curh = geth(l, r);
}
}
sort(all(v), cmp);
EACH(i, v) v1.pb(geth(i.st, i.nd));
sort(all(v1));
EACH(i, v2) ++d[getpos(i)];
FSN(i, sz(v)) {
int ln = v[i].st, rn = v[i].nd, len = rn - ln + 1;
int posh = getpos(geth(ln, rn));
rs = max(rs, 1LL * d[posh] * len);
if (ln + 1 <= rn - 1) d[getpos(geth(ln + 1, rn - 1))] += d[posh];
}
cout << rs;
return 0;
}
/*
abbabaaa
----------------------------------------------------------------
From Benq:
stuff you should look for
* int overflow, array bounds
* special cases (n=1?)
* do smth instead of nothing and stay organized
* WRITE STUFF DOWN
* DON'T GET STUCK ON ONE APPROACH
----------------------------------------------------------------
*/
Compilation message
palindrome.cpp: In function 'int main()':
palindrome.cpp:34:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
34 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
| ^
palindrome.cpp:81:5: note: in expansion of macro 'FOR'
81 | FOR(i, 1, N - 1) {
| ^~~
palindrome.cpp:34:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
34 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
| ^
palindrome.cpp:88:5: note: in expansion of macro 'FOR'
88 | FOR(i, 1, n) {
| ^~~
palindrome.cpp:35:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
35 | #define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
| ^
palindrome.cpp:92:5: note: in expansion of macro 'FOS'
92 | FOS(i, n, 1) {
| ^~~
palindrome.cpp:34:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
34 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
| ^
palindrome.cpp:96:5: note: in expansion of macro 'FOR'
96 | FOR(i, 1, n) {
| ^~~
palindrome.cpp:34:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
34 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
| ^
palindrome.cpp:119:5: note: in expansion of macro 'FOR'
119 | FOR(i, 1, n - 1) {
| ^~~
palindrome.cpp:38:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
38 | #define EACH(i, x) for (auto &(i) : (x))
| ^
palindrome.cpp:144:5: note: in expansion of macro 'EACH'
144 | EACH(i, v) v1.pb(geth(i.st, i.nd));
| ^~~~
palindrome.cpp:38:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
38 | #define EACH(i, x) for (auto &(i) : (x))
| ^
palindrome.cpp:146:5: note: in expansion of macro 'EACH'
146 | EACH(i, v2) ++d[getpos(i)];
| ^~~~
palindrome.cpp:37:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
37 | #define FSN(i, n) for (int (i) = (n) - 1; (i) >= 0; --(i))
| ^
palindrome.cpp:147:5: note: in expansion of macro 'FSN'
147 | FSN(i, sz(v)) {
| ^~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
2644 KB |
Output is correct |
2 |
Correct |
3 ms |
2636 KB |
Output is correct |
3 |
Correct |
3 ms |
2644 KB |
Output is correct |
4 |
Correct |
3 ms |
2644 KB |
Output is correct |
5 |
Correct |
3 ms |
2644 KB |
Output is correct |
6 |
Correct |
3 ms |
2644 KB |
Output is correct |
7 |
Correct |
3 ms |
2644 KB |
Output is correct |
8 |
Correct |
3 ms |
2644 KB |
Output is correct |
9 |
Correct |
3 ms |
2644 KB |
Output is correct |
10 |
Correct |
3 ms |
2644 KB |
Output is correct |
11 |
Correct |
3 ms |
2644 KB |
Output is correct |
12 |
Correct |
3 ms |
2644 KB |
Output is correct |
13 |
Correct |
3 ms |
2644 KB |
Output is correct |
14 |
Correct |
3 ms |
2644 KB |
Output is correct |
15 |
Correct |
3 ms |
2644 KB |
Output is correct |
16 |
Correct |
3 ms |
2644 KB |
Output is correct |
17 |
Correct |
4 ms |
2644 KB |
Output is correct |
18 |
Correct |
3 ms |
2644 KB |
Output is correct |
19 |
Correct |
3 ms |
2644 KB |
Output is correct |
20 |
Correct |
3 ms |
2644 KB |
Output is correct |
21 |
Correct |
3 ms |
2644 KB |
Output is correct |
22 |
Correct |
3 ms |
2644 KB |
Output is correct |
23 |
Correct |
3 ms |
2644 KB |
Output is correct |
24 |
Correct |
3 ms |
2644 KB |
Output is correct |
25 |
Correct |
3 ms |
2644 KB |
Output is correct |
26 |
Correct |
3 ms |
2644 KB |
Output is correct |
27 |
Correct |
3 ms |
2644 KB |
Output is correct |
28 |
Correct |
3 ms |
2644 KB |
Output is correct |
29 |
Correct |
3 ms |
2644 KB |
Output is correct |
30 |
Correct |
3 ms |
2644 KB |
Output is correct |
31 |
Correct |
3 ms |
2644 KB |
Output is correct |
32 |
Correct |
3 ms |
2644 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
2772 KB |
Output is correct |
2 |
Correct |
4 ms |
2772 KB |
Output is correct |
3 |
Correct |
4 ms |
2812 KB |
Output is correct |
4 |
Correct |
4 ms |
2772 KB |
Output is correct |
5 |
Correct |
4 ms |
2772 KB |
Output is correct |
6 |
Correct |
4 ms |
2772 KB |
Output is correct |
7 |
Correct |
4 ms |
2772 KB |
Output is correct |
8 |
Correct |
4 ms |
2772 KB |
Output is correct |
9 |
Correct |
4 ms |
2760 KB |
Output is correct |
10 |
Correct |
4 ms |
2644 KB |
Output is correct |
11 |
Correct |
4 ms |
2644 KB |
Output is correct |
12 |
Correct |
4 ms |
2772 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
15 ms |
3796 KB |
Output is correct |
2 |
Correct |
15 ms |
3796 KB |
Output is correct |
3 |
Correct |
20 ms |
3880 KB |
Output is correct |
4 |
Correct |
19 ms |
3940 KB |
Output is correct |
5 |
Correct |
13 ms |
3840 KB |
Output is correct |
6 |
Correct |
15 ms |
3792 KB |
Output is correct |
7 |
Correct |
16 ms |
3836 KB |
Output is correct |
8 |
Correct |
6 ms |
2984 KB |
Output is correct |
9 |
Correct |
6 ms |
3020 KB |
Output is correct |
10 |
Correct |
11 ms |
3540 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
174 ms |
13692 KB |
Output is correct |
2 |
Correct |
182 ms |
13656 KB |
Output is correct |
3 |
Correct |
244 ms |
15184 KB |
Output is correct |
4 |
Correct |
238 ms |
15240 KB |
Output is correct |
5 |
Correct |
134 ms |
13660 KB |
Output is correct |
6 |
Correct |
112 ms |
11796 KB |
Output is correct |
7 |
Correct |
162 ms |
13428 KB |
Output is correct |
8 |
Correct |
28 ms |
5524 KB |
Output is correct |
9 |
Correct |
70 ms |
7500 KB |
Output is correct |
10 |
Correct |
123 ms |
13440 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
662 ms |
37364 KB |
Output is correct |
2 |
Correct |
631 ms |
37316 KB |
Output is correct |
3 |
Correct |
980 ms |
41136 KB |
Output is correct |
4 |
Correct |
901 ms |
41432 KB |
Output is correct |
5 |
Correct |
480 ms |
37612 KB |
Output is correct |
6 |
Correct |
589 ms |
35812 KB |
Output is correct |
7 |
Correct |
611 ms |
33832 KB |
Output is correct |
8 |
Correct |
86 ms |
12532 KB |
Output is correct |
9 |
Correct |
84 ms |
12544 KB |
Output is correct |
10 |
Correct |
467 ms |
33276 KB |
Output is correct |
11 |
Correct |
575 ms |
37696 KB |
Output is correct |
12 |
Correct |
133 ms |
13144 KB |
Output is correct |