Submission #754038

#	Time	Username	Problem	Language	Result	Execution time	Memory
754038		Zflop	Secret (JOI14_secret)	C++14	100 / 100	480 ms	8200 KiB

secret

#include "secret.h"

int prefix[1000][1000], n;

void populate(int L, int R, int A[]) {
	int mid = (L + R) / 2;
	prefix[mid][mid] = A[mid];
	prefix[mid + 1][mid + 1] = A[mid + 1];

	for (int i = mid + 2; i <= R; i++)
		prefix[mid + 1][i] = Secret(prefix[mid + 1][i - 1], A[i]);
	for (int i = mid - 1; i >= L; i--)
		prefix[mid][i] = Secret(A[i], prefix[mid][i + 1]);

	if (L < mid) populate(L, mid, A);
	if (mid + 1 < R) populate(mid + 1, R, A);
}

void Init(int N, int A[]) {
	n = N;
	populate(0, N - 1, A);
}

int Query(int L, int R) {
	int a = 0, b = n - 1;
	while (a != b) {
		int mid = (a + b) / 2;
		if (mid >= L && mid < R)
			return Secret(prefix[mid][L], prefix[mid + 1][R]);
		else if (mid == R) return prefix[mid][L];
		else if (mid < L) a = mid + 1;
		else b = mid;
	}

	return prefix[a][a];
}

• Subtask 1: 100 / 100