Submission #243587

#	Time	Username	Problem	Language	Result	Execution time	Memory
243587		islingr	Palindromes (APIO14_palindrome)	C++14	0 / 100	1098 ms	34816 KiB

palindrome

#include <bits/stdc++.h>
using namespace std;

const int N = 5 << 16, A = 26;
int link[N], len[N], nxt[N][A], occ[N], v = 2;

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

	string s; cin >> s;

	len[1] = -1; link[1] = 1;
	len[2] = 0; link[2] = 1;

	for (int i = 0; i != s.size(); ++i) {
		int cur = v;
		while (s[i - len[cur] - 1] != s[i]) cur = link[cur];
		int &tmp = nxt[cur][s[i] - 'a'];
		if (!tmp) {
			tmp = ++v;
			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][s[i] - 'a'];
			} else link[tmp] = 2;
		}
		++occ[v];
	}

	for (int i = v; i > 2; --i) occ[link[i]] += occ[i];

	long long ans = 0;
	for (int i = 3; i <= v; ++i) ans = max(ans, 1ll * occ[i] * len[i]);
	cout << ans;
}

Compilation message (stderr)

palindrome.cpp: In function 'int main()':
palindrome.cpp:16:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i != s.size(); ++i) {
                  ~~^~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 26
• Subtask 5: 0 / 27