/*
$$$$$$$\ $$\ $$$$$$$\
$$ __$$\ \__| $$ __$$\
$$ | $$ | $$$$$$\ $$$$$$\ $$\ $$$$$$$\ $$ | $$ | $$$$$$\ $$$$$$\ $$$$$$$\ $$$$$$\
$$$$$$$\ |$$ __$$\ $$ __$$\ $$ |$$ _____|$$$$$$$\ | \____$$\ $$ __$$\ $$ _____|\____$$\
$$ __$$\ $$ / $$ |$$ | \__|$$ |\$$$$$$\ $$ __$$\ $$$$$$$ |$$ | \__|$$ / $$$$$$$ |
$$ | $$ |$$ | $$ |$$ | $$ | \____$$\ $$ | $$ |$$ __$$ |$$ | $$ | $$ __$$ |
$$$$$$$ |\$$$$$$ |$$ | $$ |$$$$$$$ |$$$$$$$ |\$$$$$$$ |$$ | \$$$$$$$\\$$$$$$$ |
\_______/ \______/ \__| \__|\_______/ \_______/ \_______|\__| \_______|\_______|
*/
#include <bits/stdc++.h>
using namespace std;
#define PB push_back
#define MP make_pair
#define INS insert
#define LB lower_bound
#define UB upper_bound
#define pii pair <int,int>
#define pll pair <long long, long long>
#define X first
#define Y second
#define _ << " " <<
#define sz(x) (int)x.size()
#define all(a) (a).begin(),(a).end()
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define FORD(i, a, b) for (int i = (a); i > (b); --i)
#define FORA(i, x) for (auto &i : x)
#define REP(i, n) FOR(i, 0, n)
#define BITS(x) __builtin_popcount(x)
#define SQ(a) (a) * (a)
#define TRACE(x) cout << #x " = " << (x) << '\n';
#define YES cout << "YES\n"
#define NO cout << "NO\n"
#define umap unordered_map
typedef long long ll;
typedef long double ld;
typedef vector <int> vi;
typedef vector <pii> vpi;
typedef vector <ll> vll;
typedef vector <pll> vpl;
typedef vector <double> vd;
typedef vector <ld> vld;
typedef vector<string> vs;
//((float) t)/CLOCKS_PER_SEC
const int MOD = 1e9 + 2015;
const double PI = acos(-1);
const int INF = 1e9 + 10;
const ll INFL = 1e18 + 10;
const int ABC = 30;
const int dx[] = {-1, 1, 0, 0};
const int dy[] = {0, 0, -1, 1};
const int dox[] = {-1, 1, 0, 0, -1, -1, 1, 1};
const int doy[] = {0, 0, -1, 1, -1, 1, -1, 1};
inline int sum(int a, int b){
if (a + b < 0)
return (a + b + MOD) % MOD;
return (a + b) % MOD;
}
inline void add(int &a, int b){
a = sum(a, b);
}
inline int mul(int a, int b){
return (ll)a * (ll)b % MOD;
}
inline int sub(int a, int b){
return (a - b + MOD) % MOD;
}
inline int fast_pot(ll pot, ll n){
ll ret = 1;
while (n){
if (n & 1LL)
ret = (ret * pot) % MOD;
pot = (pot * pot) % MOD;
n >>= 1LL;
}
return ret;
}
inline int divide(int a, int b){
return mul(a, fast_pot(b, MOD - 2));
}
ll lcm(ll a, ll b){
return abs(a * b) / __gcd(a, b);
}
inline double ccw(pii A, pii B, pii C){
return (A.X * B.Y) - (A.Y * B.X) + (B.X * C.Y) - (B.Y * C.X) + (C.X * A.Y) - (C.Y * A.X);
}
inline int CCW(pii A, pii B, pii C){
double val = ccw(A, B, C);
double eps = max(max(abs(A.X), abs(A.Y)), max(max(abs(B.X), abs(B.Y)), max(abs(C.X), abs(C.Y)))) / 1e9;
if (val <= -eps)
return -1;
if (val >= eps)
return 1;
return 0;
}
void to_upper(string &x){
REP(i, sz(x))
x[i] = toupper(x[i]);
}
void to_lower(string &x){
REP(i, sz(x))
x[i] = tolower(x[i]);
}
string its(ll x){
if (x == 0)
return "0";
string ret = "";
while (x > 0){
ret += (x % 10) + '0';
x /= 10;
}
reverse(all(ret));
return ret;
}
ll sti(string s){
ll ret = 0;
REP(i, sz(s)){
ret *= 10;
ret += (s[i] - '0');
}
return ret;
}
const int N = 1e5 + 10;
const int P = 31;
string s;
int n, sol[N][ABC], h[2][N], pot[N], destroy[N];
int get_hash(int f, int i, int l){
if (l == 0)
return 0;
return sub(h[f][i + l - 1], (i ? mul(h[f][i - 1], pot[l]) : 0));
}
int palin(int i, int l){
return get_hash(0, i, l) == get_hash(1, n - i - l, l);
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> s;
n = sz(s);
if (n == 1){
cout << 1 << '\n';
return 0;
}
h[0][0] = s[0] - 'a' + 1;
h[1][0] = s[n - 1] - 'a' + 1;
pot[0] = 1;
FOR(i, 1, n){
h[0][i] = mul(h[0][i - 1], P);
h[1][i] = mul(h[1][i - 1], P);
add(h[0][i], s[i] - 'a' + 1);
add(h[1][i], s[n - i - 1] - 'a' + 1);
pot[i] = mul(P, pot[i - 1]);
}
//provjeri neparne
ll ans = 2;
FOR(i, 1, n - 1){
int lo = 0, hi = min(i, n - i - 1);
while (lo < hi){
int mid = (lo + hi + 1) / 2;
if (palin(i - mid, mid * 2 + 1))
lo = mid;
else
hi = mid - 1;
}
int cnt = 1;
FORD(j, i - 1, i - lo - 1){
destroy[j] -= cnt;
cnt++;
}
cnt = 1;
FOR(j, i + 1, i + lo + 1){
destroy[j] -= cnt;
cnt++;
}
ans += lo + 1;
int l = i - lo - 1;
if (l < 0)
continue;
int r = i + lo + 1;
if (r >= n)
continue;
l--;
r++;
if (l < 0 || r > n){
l++;
r--;
if (l < 0 || r >= n)
continue;
sol[l][s[r] - 'a']++;
sol[r][s[l] - 'a']++;
continue;
}
lo = 0, hi = min(l + 1, n - r);
while (lo < hi){
int mid = (lo + hi + 1) / 2;
//cout << mid << '\n';
if (get_hash(1, n - l - 1, mid) == get_hash(0, r, mid))
lo = mid;
else
hi = mid - 1;
}
sol[l + 1][s[r - 1] - 'a'] += lo + 1;
sol[r - 1][s[l + 1] - 'a'] += lo + 1;
}
//provjeri parne
REP(i, n - 1){
int lo = 1, hi = min(i, n - i - 1) + 1;
while (lo < hi){
int mid = (lo + hi + 1) / 2;
if (palin(i - mid + 1, mid * 2))
lo = mid;
else
hi = mid - 1;
}
if (s[i] == s[i + 1]){
int cnt = 1;
FORD(j, i, i - lo){
destroy[j] -= cnt;
cnt++;
}
cnt = 1;
FOR(j, i + 1, i + lo + 1){
destroy[j] -= cnt;
cnt++;
}
ans += lo;
}
int l, r;
if (s[i] == s[i + 1]){
l = i - lo - 1;
if (l < 0)
continue;
r = i + lo + 1;
if (r >= n)
continue;
l--;
r++;
} else {
l = i - 1;
r = i + 2;
}
if (l < 0 || r >= n){
l++;
r--;
if (l < 0 || r >= n)
continue;
sol[l][s[r] - 'a']++;
sol[r][s[l] - 'a']++;
continue;
}
lo = 0, hi = min(l + 1, n - r);
while (lo < hi){
int mid = (lo + hi + 1) / 2;
//cout << mid << '\n';
if (get_hash(1, n - l - 1, mid) == get_hash(0, r, mid))
lo = mid;
else
hi = mid - 1;
}
sol[l + 1][s[r - 1] - 'a'] += lo + 1;
sol[r - 1][s[l + 1] - 'a'] += lo + 1;
}
//cout << ans << '\n';
ll w = ans;
REP(i, n){
REP(j, ABC){
// if (sol[i][j])
// cout << i _ char(j + 'a') _ destroy[i] _ sol[i][j] << '\n';
w = max(w, ans + sol[i][j] + destroy[i]);
}
}
cout << w << '\n';
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
24 ms |
1024 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
103 ms |
13944 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
