B. XOR-pyramid
time limit per test
2 seconds
memory limit per test
512 megabytes
input
standard input
output
standard output
For an array b
as
where ⊕
For example, f(1,2,4,8)=f(1⊕2,2⊕4,4⊕8)=f(3,6,12)=f(3⊕6,6⊕12)=f(5,10)=f(5⊕10)=f(15)=15
You are given an array a
and a few queries. Each query is represented as two integers l and r. The answer is the maximum value of f on all continuous subsegments of the array al,al+1,…,ar.
Input
The first line contains a single integer n
.
The second line contains n
integers a1,a2,…,an ( 0≤ai≤230−1) — the elements of the array.
The third line contains a single integer q
( 1≤q≤100000) — the number of queries.
Each of the next q
lines contains a query represented as two integers l, r ( 1≤l≤r≤n).
Output
Print q
lines — the answers for the queries.
Examples
Input
Copy
3 8 4 1 2 2 3 1 2
Output
Copy
5 12
Input
Copy
6 1 2 4 8 16 32 4 1 6 2 5 3 4 1 2
Output
Copy
60 30 12 3
Note
In first sample in both queries the maximum value of the function is reached on the subsegment that is equal to the whole segment.
In second sample, optimal segment for first query are [3,6]
, for second query — [2,5], for third — [3,4], for fourth — [1,2].
#define happy #include<bits/stdc++.h> using namespace std; #define ll long long #define rep(i,a,b) for(int i=a;i<=b;i++) #define all(a) (a).begin(),(a).end() #define pll pair<ll,ll> #define vi vector<int> #define pb push_back const int inf=0x3f3f3f3f; ll rd(){ ll x=0,f=1;char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();} return x*f; } const int N=5e3+10; int n,m,f[N][N]; int main(){ #ifdef happy freopen("in.txt","r",stdin); #endif int n=rd(); rep(i,1,n) f[i][i]=rd(); int i,j; rep(k,1,n-1) for(i=1;(j=i+k)<=n;i++) f[i][j]=f[i][j-1]^f[i+1][j]; rep(k,1,n-1) for(i=1;(j=i+k)<=n;i++) f[i][j]=max(f[i][j],max(f[i][j-1],f[i+1][j])); int m=rd(); while(m--){ i=rd(),j=rd(); printf("%d\n",f[i][j]); } }