Submission #399778

#	Time	Username	Problem	Language	Result	Execution time	Memory
399778		BERNARB01	Palindromes (APIO14_palindrome)	C++17	100 / 100	34 ms	41124 KiB

palindrome

#include <bits/stdc++.h>

using namespace std;

const int N = 3e5 + 1, A = 26;
int L[N], P[N], T[N][A], C[N];
int sP[N], diff[N], SA[N];
int id, cr, II;
char s[N];

class eertree {
private:
	int n;
	int Pr(int v) {
		while(s[II - L[v] - 2] != s[II - 1]) {
			v = P[v];
		}
		return v;
	}
	void add(char c) {
		int ch = c - 'a';
		s[II++] = ch;
		cr = Pr(cr);
		if(!T[cr][ch]) {
			L[id] = L[cr] + 2;
			P[id] = T[Pr(P[cr])][ch];
			diff[id] = L[id] - L[P[id]];
			if(diff[id] == diff[P[id]]) {
				sP[id] = sP[P[id]];
			} else {
				sP[id] = P[id];
			}
			T[cr][ch] = id++;
		}
		cr = T[cr][ch];
		C[cr]++;
	}
public:
	eertree() {};
	eertree(const string& _s) {
		s[II++] = -1;
		P[0] = 1;
		L[1] = -1;
		id = 2;
		n = _s.length();
		for (int i = 0; i < n; i++) {
			add(_s[i]);
		}
	}
	long long solve() {
		vector<int> inDeg(n + 2, 0);
		for (int i = 2; i < n + 2; i++) {
			inDeg[P[i]]++;
		}
		vector<int> que;
		for (int i = 2; i < n + 2; i++) {
			if (inDeg[i] == 0) {
				que.push_back(i);
			}
		}
		for (int b = 0; b < (int) que.size(); b++) {
			int u = que[b];
			int v = P[u];
			if (v < 2) {
				continue;
			}
			C[v] += C[u];
			inDeg[v]--;
			if (inDeg[v] == 0) {
				que.push_back(v);
			}
		}
		long long res = 0;
		for (int i = 2; i < n + 2; i++) {
			res = max(res, C[i] * 1LL * L[i]);
		}
		return res;
	}
};

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	string t;
	cin >> t;
	eertree pals(t);
	cout << pals.solve() << '\n';
	return 0;
}

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