zoukankan      html  css  js  c++  java
  • CodeForces

       设f[l,r]为区间[l,r]的f值,那么可以很容易的发现f[l,r] = f[l+1,r] ^ f[l,r-1] (l<r)  or  a[l] (l==r),这个在纸上画一画就发现了。

       于是就成了一个SB题了2333

    Discription

    For an array bb of length mm we define the function ff as

    f(b)={b[1]f(b[1]b[2],b[2]b[3],,b[m1]b[m])if m=1otherwise,f(b)={b[1]if m=1f(b[1]⊕b[2],b[2]⊕b[3],…,b[m−1]⊕b[m])otherwise,

    where ⊕ is bitwise exclusive OR.

    For example, f(1,2,4,8)=f(12,24,48)=f(3,6,12)=f(36,612)=f(5,10)=f(510)=f(15)=15f(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 aa and a few queries. Each query is represented as two integers ll and rr. The answer is the maximum value of ff on all continuous subsegments of the array al,al+1,,aral,al+1,…,ar.

    Input

    The first line contains a single integer nn (1n50001≤n≤5000) — the length of aa.

    The second line contains nn integers a1,a2,,ana1,a2,…,an (0ai23010≤ai≤230−1) — the elements of the array.

    The third line contains a single integer qq (1q1000001≤q≤100000) — the number of queries.

    Each of the next qq lines contains a query represented as two integers ll, rr (1lrn1≤l≤r≤n).

    Output

    Print qq lines — the answers for the queries.

    Examples

    Input
    3
    8 4 1
    2
    2 3
    1 2
    Output
    5
    12
    Input
    6
    1 2 4 8 16 32
    4
    1 6
    2 5
    3 4
    1 2
    Output
    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][3,6], for second query — [2,5][2,5], for third — [3,4][3,4], for fourth — [1,2][1,2].

    #include<bits/stdc++.h>
    #define ll long long
    using namespace std;
    const int maxn=5005;
    int f[maxn][maxn],ans[maxn][maxn],n,Q,L,R;
    int main(){
    	scanf("%d",&n);
    	for(int i=1;i<=n;i++) scanf("%d",&f[i][i]);
    	for(int l=1;l<n;l++)
    	    for(int i=1,j=l+1;j<=n;i++,j++){
    	    	f[i][j]=f[i+1][j]^f[i][j-1];
    	    	ans[i][j]=max(f[i][j],max(ans[i+1][j],ans[i][j-1]));
    		}
    	
    	scanf("%d",&Q);
    	while(Q--) scanf("%d%d",&L,&R),printf("%d
    ",ans[L][R]);
    	
    	return 0;
    }
    

      

  • 相关阅读:
    vue项目发布到服务器之后出现空白页和图片找不到的问题
    H5中设置一个元素一直在页面的最底部
    vue项目打包出现的问题(日常记录)
    vue写H5注册页面
    vue项目中动态图片生成
    Java中boolean类型占用多少个字节
    Java将一个目录下的所有数据复制到另一个目录下
    Java使用递归找出某目录下的所有子目录以及子文件
    实现短信验证码
    C#连接Oracle数据库(直接引用dll使用)
  • 原文地址:https://www.cnblogs.com/JYYHH/p/9058066.html
Copyright © 2011-2022 走看看