// Copyright © 2022 Youngmin Park. All rights reserved.
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;
#pragma region TEMPLATE
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using vpi = vector<pii>;
using pll = pair<ll, ll>;
using vl = vector<ll>;
using vpl = vector<pll>;
using ld = long double;
template <typename T, size_t SZ>
using ar = array<T, SZ>;
template <typename T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
#define all(v) (v).begin(), (v).end()
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
constexpr int INF = 1e9;
constexpr ll LINF = 1e18;
const ld PI = acos((ld)-1.0);
constexpr int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T>
constexpr bool ckmin(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template <typename T>
constexpr bool ckmax(T &a, const T &b) { return b > a ? a = b, 1 : 0; }
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
ll fdiv(ll a, ll b) { return a / b - ((a ^ b) < 0 && a % b); } // divide a by b rounded down
#ifdef LOCAL
#include "miscellaneous/debug.h"
#else
#define dbg(...) 42
#endif
inline namespace RecursiveLambda {
template <typename Fun>
struct y_combinator_result {
Fun fun_;
template <typename T>
explicit constexpr y_combinator_result(T &&fun) : fun_(forward<T>(fun)) {}
template <typename... Args>
constexpr decltype(auto) operator()(Args &&...args) const {
return fun_(ref(*this), forward<Args>(args)...);
}
};
template <typename Fun>
decltype(auto) y_combinator(Fun &&fun) {
return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun));
}
};
#pragma endregion TEMPLATE
/**
* Description: Trie-like structure storing distinct palindromes. Also called eertree
* Edge from u to v with character c: S_v = "c" + S_u + "c"
* Suffix links: Links to the longest nontrivial palindromic suffix
* Root 1 = Length -1, Root 2 = Length 0
* Source: http://adilet.org/blog/palindromic-tree/
* Verification:
* Time complexity: O(|S|)
* Memory complexity: O(\sigma |S|) but can be reduced by not storing all edges
* Check adamant's comment - https://codeforces.com/blog/entry/13959?#comment-313090
*/
struct Node {
int to[26];
int len;
int suf_link;
};
const int MAXN = 3e5+10;
Node tree[MAXN*26];
string s;
int ind, last_suf;
bool add_char(int pos) {
int c = s[pos] - 'a';
int cur = last_suf, cur_len = 0;
while (1) {
cur_len = tree[last_suf].len;
if (pos-1-cur_len >= 0 && s[pos-1-cur_len] == s[pos]) {
break;
}
cur = tree[cur].suf_link;
}
if (tree[cur].to[c]) {
last_suf = tree[cur].to[c];
return false;
}
ind++;
tree[cur].to[c] = ind;
tree[ind].len = 2 + tree[cur].len;
if (tree[ind].len == 1) {
tree[ind].suf_link = 2;
return true;
}
while (1) {
cur = tree[cur].suf_link;
cur_len = tree[cur].len;
if (pos-1-cur_len >= 0 && s[pos-1-cur_len] == s[pos]) {
tree[ind].suf_link = tree[cur].to[c];
return true;
}
}
}
void init_tree() {
tree[1].len = 0; tree[2].len = -1;
tree[1].suf_link = tree[2].suf_link = 1;
ind = last_suf = 2;
}
void solve() {
cin >> s;
int n = sz(s);
init_tree();
for (int i = 0; i < n; i++) {
add_char(i);
}
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
int testcase = 1;
// cin >> testcase;
while (testcase--) {
solve();
}
#ifdef LOCAL
cerr << "Time elapsed: " << 1.0 * (double)clock() / CLOCKS_PER_SEC << " s.\n";
#endif
}
Compilation message
palindrome.cpp:7: warning: ignoring '#pragma region TEMPLATE' [-Wunknown-pragmas]
7 | #pragma region TEMPLATE
|
palindrome.cpp:65: warning: ignoring '#pragma endregion TEMPLATE' [-Wunknown-pragmas]
65 | #pragma endregion TEMPLATE
|
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1090 ms |
212 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1026 ms |
212 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1090 ms |
340 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1083 ms |
468 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1081 ms |
988 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
