#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#define ll long long
const int nmax = 3e5 + 5;
const ll oo = 1e18;
const int lg = 18;
const int tx = 2;
const ll base = 311;
#define pii pair<int, int>
#define fi first
#define se second
#define debug(a, n) for(int i = 1; i <= n; ++i) cout << a[i] << ' ';
using namespace std;
ll mod[] = {(int)1e9 + 7, (int)1e9 + 9};
int n, cur = 0;
string s;
int pw[nmax][2], h[nmax][2];
int D_odd[nmax];
int D_even[nmax];
void Calc_D_odd() {
int L = 1;
int R = 0;
for(int i = 1 ; i <= n; i++) {
if(i > R) D_odd[i] = 0;
else D_odd[i] = min(R - i, D_odd[L + (R - i)]);
while(i - D_odd[i] - 1 > 0 && i + D_odd[i] + 1 <= n && s[i - D_odd[i] - 1] == s[i + D_odd[i] + 1]) {
D_odd[i]++;
}
if(i + D_odd[i] > R) {
R = i + D_odd[i];
L = i - D_odd[i];
}
}
}
void Calc_D_even() {
int L = 1;
int R = 0;
for(int i = 1 ; i < n; i++) {
int j = i + 1;
if(j > R) D_even[i] = 0;
else D_even[i] = min(R - j + 1, D_even[L + (R - j)]);
while(i - D_even[i] > 0 && j + D_even[i] <= n && s[i - D_even[i]] == s[j + D_even[i]]) {
D_even[i]++;
}
if(i + D_even[i] > R) {
R = i + D_even[i];
L = j - D_even[i];
}
}
}
void Init(){
for(int j = 0; j < tx; ++j) pw[j][0] = 1;
for(int i = 1, j; i <= n; ++i){
for(int j = 0; j < tx; ++j){
pw[i][j] = 1ll * pw[i - 1][j]* base % mod[j];
h[i][j] = (1ll * h[i - 1][j] * base + s[i] - 'a' + 1) % mod[j];
}
}
}
int get(int l, int r, int ix){
return (h[r][ix] - 1ll * h[l - 1][ix] * pw[r - l + 1][ix] + 1ll * mod[ix] * mod[ix]) % mod[ix];
}
map<ll, bool> mp;
map<ll, int> ind;
int cnt[nmax], f[nmax], b[nmax];
vector<int> adj[nmax];
void update(int l, int r){
bool ok = 1;int sz = 0;
while(l <= r){
ll x = 1ll * get(l, r, 0) * (1ll << 32) + get(l, r, 1);
if(!mp[x]){
ind[x] = ++cur;
b[++sz] = cur;
if(ok){
f[cur]++;
ok = 0;
}
cnt[cur] = r - l + 1;
mp[x] = 1;
}
else{
int id = ind[x];
b[++sz] = id;
if(ok) f[id]++;
break;
}
++l, --r;
}
if(l > r) b[++sz] = 0;
for(int i = 1, x, y; i < sz; ++i){
x = b[i], y = b[i + 1];
adj[y].push_back(x);
}
}
void dfs(int u){
for(auto v : adj[u]){
dfs(v);
f[u] += f[v];
}
}
main(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
// freopen("code.inp", "r", stdin);
// freopen("code.out", "w", stdout);
cin >> s;
n = s.size(); s = ' ' + s + ' ';
Init();
Calc_D_odd();
Calc_D_even();
for(int i = n; i >= 1; --i){
update(i - D_odd[i], i + D_odd[i]);
if(i < n) update(i - D_even[i] + 1, i + D_even[i]);
}
dfs(0);
ll ans = 0;
for(int i = 1; i <= cur; ++i){
ans = max(ans, 1ll * f[i] * cnt[i]);
}
cout << ans;
}
/*
*/
Compilation message
palindrome.cpp: In function 'void Init()':
palindrome.cpp:61:20: warning: unused variable 'j' [-Wunused-variable]
61 | for(int i = 1, j; i <= n; ++i){
| ^
palindrome.cpp: At global scope:
palindrome.cpp:113:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
113 | main(){
| ^~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
14940 KB |
Output is correct |
| 2 |
Incorrect |
3 ms |
14940 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
256 ms |
54024 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
280 ms |
125296 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
287 ms |
127000 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
2595 ms |
131072 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
