Submission #524581

#	Time	Username	Problem	Language	Result	Execution time	Memory
524581		fcw	Necklace (Subtask 4) (BOI19_necklace4)	C++17	0 / 15	89 ms	65540 KiB

necklace

#include <bits/stdc++.h>
#define st first
#define nd second
using lint = int64_t;
constexpr int MOD = int(1e9) + 7;
constexpr int INF = 0x3f3f3f3f;
constexpr int NINF = 0xcfcfcfcf;
constexpr lint LINF = 0x3f3f3f3f3f3f3f3f;
const long double PI = acosl(-1.0);
// Returns -1 if a < b, 0 if a = b and 1 if a > b.
int cmp_double(double a, double b = 0, double eps = 1e-9) {
	return a + eps > b ? b + eps > a ? 0 : 1 : -1;
}
using namespace std;

vector<int> Z(const string& S) {
    vector<int> z(S.size());
    int l = -1, r = -1;
    for(int i = 1; i < int(S.size()); ++i) {
        z[i] = i >= r ? 0 : min(r - i, z[i - l]);
        while (i + z[i] < int(S.size()) && S[i + z[i]] == S[z[i]])
            z[i]++;
        if (i + z[i] > r) l = i, r = i + z[i];
    }
    return z;
}

int main() {
	cin.tie(nullptr)->sync_with_stdio(false);
	string s, t;
	cin>>s>>t;
	int n = (int)s.size(), m = (int)t.size();
	string rt = t;
	reverse(rt.begin(), rt.end());
	vector<vector<int>>z(n), rz(n);
	for(int i=0;i<n;i++){
		z[i] = Z(s + t), rz[i] = Z(s + rt);
		for(int j=0;j<m;j++){
			z[i][n+j] = min(z[i][n+j], n-i);
			rz[i][n+j] = min(rz[i][n+j], n-i);
		}
		rotate(s.begin(), s.begin() + 1, s.end());
	}
	vector<vector<int>>w(n, vector<int>(m));
	vector<vector<int>>rw(n, vector<int>(m));
	int ans = 0;
	pair<int, int>ind = {-1, -1};
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			int d = z[i][n+j], rd = rz[i][n+j];
			if(d){
				if(ans < d) ans = d, ind = {i, j};
				int ni = i + d, nj = j + d;
				if(ni < n) w[ni][j] = max(w[ni][j], d);
				if(nj < m){
					int nd = w[i][nj];
					if(ans < d+nd) ans = d+nd, ind = {i-d, j};
				}
			}
			if(rd){
				if(ans < rd) ans = rd, ind = {i, m-(j+rd)};
				int ni = i + rd, nj = j + rd;
				if(ni < n) rw[ni][j] = max(rw[ni][j], rd);
				if(nj < m){
					int nd = rw[i][nj];
					if(ans < rd+nd) ans = rd+nd, ind = {i-rd, m-(j+rd+nd)};
				}
			}
		}
	}
	cout<<ans<<"\n";
	cout<<ind.st<<" "<<ind.nd<<"\n";
	return 0;
}
/*
[  ]Leu o problema certo???
[  ]Ver se precisa de long long
[  ]Viu o limite dos fors (é n? é m?)
[  ]Tamanho do vetor, será que é 2e5 em vez de 1e5??
[  ]Testar sample
[  ]Testar casos de  borda
[  ]1LL no 1LL << i
[  ]Testar mod (é 1e9+7, mesmo?, será que o mod não ficou negativo?)
*/

• Subtask 1: 0 / 15