Submission #954532

#	Time	Username	Problem	Language	Result	Execution time	Memory
954532		IBory	Secret (JOI14_secret)	C++17	100 / 100	398 ms	5148 KiB

secret

#include "secret.h"
#include <bits/stdc++.h>
#define pii pair<int, int>
using namespace std;

const int MAX = 1004;
map<pii, int> D;
int N, S[MAX];

void DnC1(int L, int R) {
	if (L >= R) return;
	int mid = (L + R) >> 1;

	int pv = -1;
	for (int i = mid - 1; i >= L; --i) {
		int n = -1;
		if (pv == -1) n = Secret(S[i], S[mid]);
		else n = Secret(S[i], pv);
		pv = D[{i, mid}] = n;
	}
	pv = -1;
	for (int i = mid + 2; i <= R; ++i) {
		int n = -1;
		if (pv == -1) n = Secret(S[mid + 1], S[i]);
		else n = Secret(pv, S[i]);
		pv = D[{mid + 1, i}] = n;
	}

	DnC1(L, mid);
	DnC1(mid + 1, R);
}

void Init(int _N, int A[]) {
	N = _N;
	for (int i = 0; i < N; ++i) S[i] = A[i];
	DnC1(0, N - 1);
	for (int i = 0; i < N; ++i) D[{i, i}] = A[i];
}

int DnC2(int L, int R, int s, int e) {
	if (L >= R) return -1;
	int mid = (L + R) >> 1;

	if (s <= mid && mid < e) {
		int a = D[{s, mid}], b = D[{mid + 1, e}];
		return Secret(a, b);
	}

	if (e <= mid) return DnC2(L, mid, s, e);
	else return DnC2(mid + 1, R, s, e);
}

int Query(int L, int R) {
	if (D.find(pii{L, R}) != D.end()) return D[{L, R}];
	return DnC2(0, N - 1, L, R);
}

• Subtask 1: 100 / 100