#include "secret.h" #include <bits/stdc++.h> using namespace std; const int mxN = 1010; const int mxLg = 10; int n, a[mxN], ans[mxLg][mxN], mask[mxN]; void dnc(int l, int r, int lev){ if(l==r) return; int m = (l+r)/2; ans[lev][m]=a[m], ans[lev][m+1]=a[m+1]; for(int i = m-1; i>=l; i--) ans[lev][i] = Secret(a[i],ans[lev][i+1]); for(int i = m+2; i<=r; i++) ans[lev][i] = Secret(ans[lev][i-1],a[i]); for(int i = m+1; i<=r; i++) mask[i]^=(1<<lev); dnc(l,m,lev+1), dnc(m+1,r,lev+1); } void Init(int N, int A[]) { for(int i = 0; i < N; i++) a[i]=A[i]; dnc(0,N-1,0); n=N; } int Query(int L, int R) { if(L==R) return a[L]; int m = __builtin_ctz(mask[L]^mask[R]); return Secret(ans[m][L],ans[m][R]); }