#include <bits/stdc++.h>
#define int long long
#define f(i, a, b) for(int i = a; i <= b; i++)
#define fr(i, a, b) for(int i = a; i >= b; i--)
#define pii pair <int, int>
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define in insert
#define vvec vector<vector<int>>
#define fast ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0)
using namespace std;
const int N = 3e5 + 5;
const int mod = 1e9 + 7;
const int base = 31;
int n, Hash[N], Pow[N];
unordered_map <int, int> mp;
string s;
int get(int i, int j)
{
return (Hash[j] - Hash[i - 1] * Pow[j - i + 1] + mod * mod) % mod;
}
void sub2()
{
int res = 0;
f(i, 1, n)
{
int t = 0;
while(i - t >= 1 && i + t <= n && s[i - t] == s[i + t])
{
int z = ++mp[get(i - t, i + t)];
// cout << get(i - t, i + t) << "\n";
//cout << i << " " << z << " " << (2 * t + 1) << "\n";
res = max(res, (2 * t + 1) * z);
t++;
}
t = 0; int j = i + 1;
while(i - t >= 1 && j + t <= n && s[i - t] == s[j + t])
{
int z = ++mp[get(i - t, j + t)];
//cout << get(i - t, j + t) << "\n";
//cout << i << " " << z << " " << (2 * t + 2) << "\n";
res = max(res, (2 * t + 2) * z);
t++;
}
}
cout << res;
}
signed main()
{
fast;
if(fopen("palindrome.in", "r"))
{
freopen("palindrome.in", "r", stdin);
freopen("palindrome.out", "w", stdout);
}
cin >> s;
n = s.size(); s = '!' + s;
Pow[0] = 1;
f(i, 1, n)
{
//a[i] = s[i] - 'a';
Hash[i] = (Hash[i - 1] * base + (s[i] - 'a' + 1)) % mod;
Pow[i] = (Pow[i - 1] * base) % mod;
}
sub2();
//int l = 0,
}
Compilation message
palindrome.cpp: In function 'int main()':
palindrome.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
61 | freopen("palindrome.in", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
palindrome.cpp:62:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
62 | freopen("palindrome.out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
344 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
1 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
344 KB |
Output is correct |
9 |
Correct |
0 ms |
344 KB |
Output is correct |
10 |
Correct |
1 ms |
344 KB |
Output is correct |
11 |
Correct |
1 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
468 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Correct |
0 ms |
344 KB |
Output is correct |
15 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
0 ms |
464 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
1 ms |
348 KB |
Output is correct |
20 |
Correct |
1 ms |
348 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
0 ms |
348 KB |
Output is correct |
23 |
Correct |
0 ms |
348 KB |
Output is correct |
24 |
Correct |
0 ms |
348 KB |
Output is correct |
25 |
Correct |
0 ms |
348 KB |
Output is correct |
26 |
Correct |
0 ms |
348 KB |
Output is correct |
27 |
Correct |
0 ms |
348 KB |
Output is correct |
28 |
Correct |
0 ms |
424 KB |
Output is correct |
29 |
Correct |
0 ms |
612 KB |
Output is correct |
30 |
Correct |
1 ms |
476 KB |
Output is correct |
31 |
Correct |
0 ms |
360 KB |
Output is correct |
32 |
Correct |
1 ms |
360 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
548 KB |
Output is correct |
2 |
Correct |
2 ms |
360 KB |
Output is correct |
3 |
Correct |
7 ms |
360 KB |
Output is correct |
4 |
Correct |
2 ms |
612 KB |
Output is correct |
5 |
Correct |
7 ms |
360 KB |
Output is correct |
6 |
Correct |
7 ms |
348 KB |
Output is correct |
7 |
Correct |
1 ms |
348 KB |
Output is correct |
8 |
Correct |
4 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
352 KB |
Output is correct |
10 |
Correct |
0 ms |
412 KB |
Output is correct |
11 |
Correct |
0 ms |
344 KB |
Output is correct |
12 |
Correct |
1 ms |
344 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
452 ms |
1108 KB |
Output is correct |
2 |
Correct |
214 ms |
908 KB |
Output is correct |
3 |
Correct |
849 ms |
900 KB |
Output is correct |
4 |
Correct |
603 ms |
1364 KB |
Output is correct |
5 |
Correct |
2 ms |
860 KB |
Output is correct |
6 |
Correct |
16 ms |
860 KB |
Output is correct |
7 |
Correct |
64 ms |
772 KB |
Output is correct |
8 |
Correct |
1 ms |
604 KB |
Output is correct |
9 |
Correct |
1 ms |
604 KB |
Output is correct |
10 |
Correct |
2 ms |
860 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1028 ms |
4672 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1059 ms |
6672 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |