Submission #243618

#	Time	Username	Problem	Language	Result	Execution time	Memory
243618		islingr	Palindromes (APIO14_palindrome)	C++14	100 / 100	34 ms	35068 KiB

palindrome

#include <iostream>
using namespace std;

const int N = 5 << 16, A = 26;
int link[N], len[N], nxt[N][A], occ[N], cnt = 2, lst = 2;
char s[N];

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	cin >> s;
	len[1] = -1; link[1] = 1;
	len[2] = -0; link[2] = 1;
	for (int i = 0; s[i]; ++i) {
		int cur = lst, a = s[i] - 'a';
		while (s[i - len[cur] - 1] != s[i]) cur = link[cur];
		int &tmp = nxt[cur][a];
		if (!tmp) {
			tmp = ++cnt;
			len[tmp] = len[cur] + 2;
			if (cur != 1) {
				cur = link[cur];
				while (s[i - len[cur] - 1] != s[i]) cur = link[cur];
				link[tmp] = nxt[cur][a];
			} else link[tmp] = 2;
		}
		lst = tmp; ++occ[lst];
	}
	long long ans = 0;
	for (int i = cnt; i > 2; --i) {
		occ[link[i]] += occ[i];
		ans = max(ans, 1ll * occ[i] * len[i]);
	}
	cout << ans;
}

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