oj.uz

답안 #207303

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
207303 2020-03-07T05:37:58 Z dolphingarlic Palinilap (COI16_palinilap) C++14
54 / 100
 71 ms 24952 KB 
#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
typedef unsigned long long ull;
using namespace std;

const ull P = 37;

ull pw[100001];

int n;
string s[2];
ull hsh[100001][2];
ll created[100001][26], destroyed[100001][2];

void calc_hashes() {
	hsh[0][0] = hsh[0][1] = 1;
	FOR(i, 0, n) FOR(j, 0, 2)
		hsh[i + 1][j] = hsh[i][j] * P + (s[j][i] - 'a' + 1);
}

ull get_hash(int a, int b, bool reverse) {
	return hsh[b + 1][reverse] - hsh[a][reverse] * pw[b - a + 1];
}

bool is_palindrome(int a, int b, int c, int d) {
	return get_hash(a, b, false) == get_hash(n - d - 1, n - c - 1, true);
}

int main() {
	cin >> s[0];
	n = s[0].size();
	s[1] = s[0];
	reverse(s[1].begin(), s[1].end());
	
	pw[0] = 1;
	FOR(i, 0, n) pw[i + 1] = P * pw[i];
	calc_hashes();
	
	ll base = 0;
	FOR(i, 0, n) FOR(j, i, i + 2) {
		int l = 0, r = min(i + 1, n - j);
		while (l != r) {
			int mid = (l + r + 1) / 2;
			if (is_palindrome(i - mid + 1, i, j, j + mid - 1)) l = mid;
			else r = mid - 1;
		}
		int rad = r;
		base += rad;
		
		if (i == j) {
			destroyed[j + 1][0]--, destroyed[j + rad][0]++;
			destroyed[j + 1][1] += j + rad, destroyed[j + rad][1] -= j + rad;

			destroyed[i - rad + 1][0]++, destroyed[i][0]--;
			destroyed[i - rad + 1][1] -= i - rad, destroyed[i][1] += i - rad;
		} else {
			destroyed[j][0]--, destroyed[j + rad][0]++;
			destroyed[j][1] += j + rad, destroyed[j + rad][1] -= j + rad;

			destroyed[i - rad + 1][0]++, destroyed[i + 1][0]--;
			destroyed[i - rad + 1][1] -= i - rad, destroyed[i + 1][1] += i - rad;
		}
		
		int x = i - rad, y = j + rad;
		if (x < 0 || y >= n) continue;
		
		rad++;
		l = 0, r = min(i + 1, n - j) - rad;
		while (l != r) {
			int mid = (l + r + 1) / 2;
			if (is_palindrome(x - mid, x - 1, y + 1, y + mid)) l = mid;
			else r = mid - 1;
		}

		created[x][s[0][y] - 'a'] += r + 1;
		created[y][s[0][x] - 'a'] += r + 1;
	}
	
	ll best = 0, x = 0, y = 0;
	FOR(i, 0, n) {
		x += destroyed[i][0], y += destroyed[i][1];
		FOR(j, 0, 26) if (i != s[0][j] - 'a') {
			best = max(best, created[i][j] - i * x - y);
		}
	}
	
	cout << base + best;
	return 0;
}

Subtask #1
17.0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 376 KB Output is correct
2 Correct 4 ms 376 KB Output is correct
3 Correct 5 ms 376 KB Output is correct
4 Correct 5 ms 376 KB Output is correct
5 Correct 5 ms 376 KB Output is correct

Subtask #2
37.0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 1656 KB Output is correct
2 Correct 7 ms 1532 KB Output is correct
3 Correct 7 ms 1528 KB Output is correct
4 Correct 6 ms 1144 KB Output is correct
5 Correct 7 ms 1400 KB Output is correct
6 Correct 7 ms 1528 KB Output is correct
7 Correct 7 ms 1528 KB Output is correct

Subtask #3
0 / 46.0

# 결과 실행 시간 메모리 Grader output
1 Correct 64 ms 24824 KB Output is correct
2 Correct 49 ms 24824 KB Output is correct
3 Correct 50 ms 24952 KB Output is correct
4 Correct 61 ms 24800 KB Output is correct
5 Correct 65 ms 24824 KB Output is correct
6 Correct 62 ms 24824 KB Output is correct
7 Correct 62 ms 24828 KB Output is correct
8 Correct 37 ms 4472 KB Output is correct
9 Correct 64 ms 24824 KB Output is correct
10 Correct 61 ms 24824 KB Output is correct
11 Correct 47 ms 24828 KB Output is correct
12 Correct 65 ms 24824 KB Output is correct
13 Correct 71 ms 24824 KB Output is correct
14 Correct 61 ms 24824 KB Output is correct
15 Correct 63 ms 24824 KB Output is correct
16 Correct 58 ms 24824 KB Output is correct
17 Correct 60 ms 24824 KB Output is correct
18 Incorrect 65 ms 24824 KB Output isn't correct
19 Halted 0 ms 0 KB -