#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int k_N = 1e6 + 3;
const int cnt_Mod = 2;
const array<ll, cnt_Mod> k_Mod{(int)1e9 + 7, (int)1e9 + 93}, k_Base{293, 353};
int dp[k_N];
string s;
int n;
array<ll, cnt_Mod> h[k_N], b_pow[k_N];
ll get_hash(int l, int r, int idx){
if(l == 0) return h[r][idx];
ll ans = (h[r][idx] - h[l - 1][idx] * b_pow[r - l + 1][idx]) % k_Mod[idx];
return (ans < 0) ? (ans + k_Mod[idx]) : ans;
}
bool equal(int l1, int r1, int l2, int r2){
return s.subtr(l1, r1 - l1 + 1) == s.substr(l2, r2 - l2 + 1);
for(int i = 0; i < cnt_Mod; ++i)
if(get_hash(l1, r1, i) != get_hash(l2, r2, i))
return false;
return true;
}
void init_hashing(){
for(int i = 0; i < n; ++i){
for(int j = 0; j < cnt_Mod; ++j){
if(i == 0)
h[i][j] = s[i];
else
h[i][j] = (h[i - 1][j] * k_Base[j] + s[i]) % k_Mod[j];
}
}
for(int i = 0; i < n; ++i){
for(int j = 0; j < cnt_Mod; ++j){
if(i == 0)
b_pow[i][j] = 1;
else
b_pow[i][j] = b_pow[i - 1][j] * k_Base[j] % k_Mod[j];
}
}
}
void solve(){
cin >> s;
n = (int)s.size();
init_hashing();
int mid = (n - 1) / 2, mid2 = (n - 2) / 2;
dp[mid + 1] = 0;
for(int i = mid; i >= 0; --i){
dp[i] = 1;
for(int j = i; j <= mid2; ++j){
if(equal(i, j, n - j - 1, n - i - 1)){
//cout << "equal " << i << " " << j << " " << n - j - 1 << " " << n - i - 1 << "\n";
dp[i] = max(dp[j + 1] + 2, dp[i]);
}
//else
// cout << "NOT equal " << i << " " << j << " " << n - j - 1 << " " << n - i - 1 << "\n";
}
}
cout << dp[0] << "\n";
}
int main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
int t;
cin >> t;
while(t--)
solve();
}
Compilation message
palindromic.cpp: In function 'bool equal(int, int, int, int)':
palindromic.cpp:24:14: error: 'std::__cxx11::string {aka class std::__cxx11::basic_string<char>}' has no member named 'subtr'; did you mean 'substr'?
return s.subtr(l1, r1 - l1 + 1) == s.substr(l2, r2 - l2 + 1);
^~~~~
substr
