Submission #402692

#	Time	Username	Problem	Language	Result	Execution time	Memory
402692		BERNARB01	Palindromes (APIO14_palindrome)	C++17	100 / 100	28 ms	35400 KiB

palindrome

#include <bits/stdc++.h>

using namespace std;

template<const int A>
class eertree {
private:
	string s;
	int n, id, cr, I;
	vector<int> P, L, C;
	vector<array<int, A>> T;
	int par(int v) {
		while (I - L[v] - 2 < 0 || s[I - L[v] - 2] != s[I - 1]) {
			v = P[v];
		}
		return v;
	}
	void add() {
		int ch = s[I++] - 'a';
		cr = par(cr);
		if (!T[cr][ch]) {
			L[id] = L[cr] + 2;
			P[id] = T[par(P[cr])][ch];
			T[cr][ch] = id++;
		}
		cr = T[cr][ch];
		C[cr]++;
	}
public:
	eertree(const string& _s) {
		s = _s;
		n = s.length();
		id = 2;
		cr = I = 0;
		P.assign(n + 2, 0);
		L.assign(n + 2, 0);
		C.assign(n + 2, 0);
		T.assign(n + 2, {});
		L[1] = -1;
		P[0] = 1;
		for (int i = 0; i < n; i++) {
			add();
		}
	}
	long long solve() {
		for (int i = n + 1; i > 1; i--) {
			C[P[i]] += C[i];
		}
		long long res = 0;
		for (int i = 2; i < n + 2; i++) {
			res = max(res, L[i] * 1LL * C[i]);
		}
		return res;
	}
};

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	string s;
	cin >> s;
	cout << eertree<26>(s).solve() << '\n';
	return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 26 / 26
• Subtask 5: 27 / 27