Submission #784421

#	Time	Username	Problem	Language	Result	Execution time	Memory
784421		chanhchuong123	Secret (JOI14_secret)	C++14	100 / 100	418 ms	4504 KiB

secret

#include "secret.h"
#include <bits/stdc++.h>
using namespace std;

const int MAX = 200200;
int n;
int a[MAX];
int mask[MAX];
int dp[18][MAX];

void divide(int l, int r, int level) {
    if (l == r) return;
    int mid = l + r >> 1;
    dp[level][mid] = a[mid]; dp[level][mid + 1] = a[mid + 1];
    for (int i = mid - 1; i >= l; --i) dp[level][i] = Secret(a[i], dp[level][i + 1]);
    for (int i = mid + 2; i <= r; ++i) dp[level][i] = Secret(dp[level][i - 1], a[i]);
    for (int i = mid + 1; i <= r; ++i) mask[i] ^= 1 << level;
    divide(l, mid, level + 1); divide(mid + 1, r, level + 1);
}

void Init(int N, int A[]) {
    n = N;
    for (int i = 0; i < n; ++i) {
        a[i] = A[i];
      	mask[i] = 0;
    }
    divide(0, n - 1, 0);
}

int Query(int L, int R) {
    if (L == R) return a[L];
    int lev = __builtin_ctz(mask[L] ^ mask[R]);
    return Secret(dp[lev][L], dp[lev][R]);
}

Compilation message (stderr)

secret.cpp: In function 'void divide(int, int, int)':
secret.cpp:13:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   13 |     int mid = l + r >> 1;
      |               ~~^~~

• Subtask 1: 100 / 100