Submission #926621

#	Time	Username	Problem	Language	Result	Execution time	Memory
926621		myst6	Secret (JOI14_secret)	C++14	100 / 100	395 ms	4568 KiB

secret

#include <bits/stdc++.h>
#include "secret.h"

const int maxn = 1000;
int table[10][maxn];
int mask[maxn];
int base[maxn];

void fill(int L, int R, int B) {
  if (L == R) return;
  int M = (L + R) / 2;
  table[B][M] = base[M];
  table[B][M+1] = base[M+1];
  for (int i=M-1; i>=L; i--) table[B][i] = Secret(base[i], table[B][i+1]);
  for (int i=M+2; i<=R; i++) table[B][i] = Secret(table[B][i-1], base[i]);
  for (int i=M+1; i<=R; i++) mask[i] ^= 1 << B;
  fill(L, M, B+1);
  fill(M+1, R, B+1);
}

void Init(int N, int A[]) {
  std::memset(mask, 0, sizeof mask);
  for (int i=0; i<N; i++) base[i] = A[i];
  fill(0, N-1, 0);
}

int Query(int L, int R) {
  if (L == R) return base[L];
  int B = __builtin_ctz(mask[L] ^ mask[R]);
  return Secret(table[B][L], table[B][R]);
}

• Subtask 1: 100 / 100