Submission #867047

#	Time	Username	Problem	Language	Result	Execution time	Memory
867047		serifefedartar	Necklace (Subtask 1-3) (BOI19_necklace1)	C++17	85 / 85	176 ms	604 KiB

necklace

#include <bits/stdc++.h>
using namespace std;
 
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 1e9+9;
const ll P = 31;
const ll LOGN = 20; 
const ll MAXN = 1e5 + 5;

int ans[3], n, m;
int p1[MAXN], p2[MAXN];
void compute(string s, int p_array[]) {
	int q = s.length();
	p_array[0] = 0;
	for (int i = 1; i < q; i++) {
		int j = p_array[i-1];
		while (j && s[i] != s[j])
			j = p_array[j-1];
		if (s[i] == s[j])
			j++;
		p_array[i] = j;
	}
}

void solve(string s, string t, bool rev) {
	string t_rev = t;
	reverse(t_rev.begin(), t_rev.end());
	for (int i = 0; i < n; i++) {
		string l_up = s.substr(0, i), r_up = s.substr(i, n);

		reverse(l_up.begin(), l_up.end());
		string for_a = l_up + "#" + t;
		string for_b = r_up + "#" + t_rev;
		compute(for_a, p1);
		compute(for_b, p2);

		for (int j = 1; j <= m; j++) {
			int a = p1[i+j];
			int b = p2[n+m-i-j];
			if (a + b > ans[0]) {
				ans[0] = a + b;
				ans[1] = i - p1[i+j];
				ans[2] = (rev ? m - j - b : j - a);
			}
		}
	}
}

int main() {
	fast
	string s, t;
	cin >> s >> t;
	n = s.size(), m = t.size();

	solve(s, t, 0);
	reverse(t.begin(), t.end());
	solve(s, t, 1);
	cout << ans[0] << "\n" << ans[1] << " " << ans[2] << "\n";
}

• Subtask 1: 25 / 25
• Subtask 2: 20 / 20
• Subtask 3: 40 / 40