제출 #399128

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
399128		BERNARB01	회문 (APIO14_palindrome)	C++17	23 / 100	1090 ms	6832 KiB

palindrome

#pragma GCC optimize("Ofast")
#pragma GCC optimization ("O3")
#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>

using namespace std;

void Z(const string& s, vector<int>& z) {
		z.assign(s.size(), 0);
    int n = s.size();
    int x = 0, y = 0;
    for (int i = 1; i < n; i++) {
        z[i] = max(0, min(z[i-x], y-i+1));
        while (i+z[i] < n && s[z[i]] == s[i+z[i]]) {
            x = i; y = i+z[i]; z[i]++;
        }
    }
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//freopen("palindrome.in", "r", stdin);
	//freopen("palindrome.out", "w", stdout);
	string s;
	cin >> s;
	int n = s.length();
	vector<int> z, cnt(n + 1, 0);
	vector<bool> pal(n + 1, false);
	long long res = 0;
	for (int i = 0; i < n; i++) {
		string t = s.substr(i, n - i);
		string rt = t;
		reverse(rt.begin(), rt.end());
		string t2 = t;
		t2 += '#';
		t2 += rt;
		Z(t2, z);
		for (int j = 0; j <= n - i; j++) {
			pal[j] = false;
			cnt[j] = 0;
		}
		for (int j = 0; j < n - i; j++) {
			if (z[z.size() - j - 1] == j + 1) {
				pal[j] = 1;
			}
		}
		t += '#';
		t += s;
		Z(t, z);
		for (int j = n - i + 1; j < (int) z.size(); j++) {
			cnt[z[j]]++;
		}
		for (int j = n - i - 1; j >= 0; j--) {
			cnt[j] += cnt[j + 1];
		}
		for (int j = i; j < n; j++) {
			if (pal[j - i]) {
				int len = j - i + 1;
				res = max(res, cnt[len] * 1LL * len);
			}
		}
	}
	cout << res << '\n';
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

palindrome.cpp:2: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    2 | #pragma GCC optimization ("O3")
      |

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