CodeForces768B:Code For 1 (分治)
Jon fought bravely to rescue the wildlings who were attacked by the white-walkers at Hardhome. On his arrival, Sam tells him that he wants to go to Oldtown to train at the Citadel to become a maester, so he can return and take the deceased Aemon's place as maester of Castle Black. Jon agrees to Sam's proposal and Sam sets off his journey to the Citadel. However becoming a trainee at the Citadel is not a cakewalk and hence the maesters at the Citadel gave Sam a problem to test his eligibility.
Initially Sam has a list with a single element n. Then he has to perform certain operations on this list. In each operation Sam must remove any element x, such that x > 1, from the list and insert at the same position ,
,
sequentially. He must continue with these operations until all the elements in the list are either 0 or 1.
Now the masters want the total number of 1s in the range l to r (1-indexed). Sam wants to become a maester but unfortunately he cannot solve this problem. Can you help Sam to pass the eligibility test?
Input
The first line contains three integers n, l, r (0 ≤ n < 250, 0 ≤ r - l ≤ 105, r ≥ 1, l ≥ 1) – initial element and the range l to r.
It is guaranteed that r is not greater than the length of the final list.
Output
Output the total number of 1s in the range l to r in the final sequence.
Examples
7 2 5
4
10 3 10
5
Note
Consider first example:
Elements on positions from 2-nd to 5-th in list is [1, 1, 1, 1]. The number of ones is 4.
For the second example:
Elements on positions from 3-rd to 10-th in list is [1, 1, 1, 0, 1, 0, 1, 0]. The number of ones is 5.
题意:一开始有一个数N,每次把所有大于1的数变为x/2,x%2,x/2。知道不能操作。样例如题。
思路:找规律我们得知,最后的01串有很多的对称性。首先推出最后一层有num=2^(lg2(N)+1) -1个数,并且以x=(num+1)/2为对称轴,所以如果在对称轴的右边,我们可以把它对称到x轴的左边。 然后把对称轴左边的区间[1,x]又看成一个整体,它又以x2=(x+1)/2为对称轴,如果在x2右边,又把它对称到x2左边.....一直对称下去,直到把它对称到一个对称轴上。而我们可以求出对称轴上对应的数的值,就是N的二进制对应的数。
比如10的二进制表示为10(ten)=1010(two)。10=1(1)+0(2)+1(4)+0(8),(括号里的是最后一层的对称轴位置,也是最后一层二进制对应位置的结果)。
(ps:也可以用分形来做。
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn=;
ll find(ll x){
ll y=log2(x);
if(1LL<<y==x) return y;
return find((1LL<<(y+))-x);
}
int main()
{
ll N,L,R,ans=,Bit;
cin>>N>>L>>R;
Bit=log2(N);
for(ll i=L;i<=R;i++)
ans+=(N>>(Bit-find(i)))&1LL;
cout<<ans<<endl;
return ;
}
CodeForces768B:Code For 1 (分治)的更多相关文章
- Codeforces768B Code For 1 2017-02-21 22:17 95人阅读 评论(0) 收藏
B. Code For 1 time limit per test 2 seconds memory limit per test 256 megabytes input standard input ...
- code for 1 - 分治
2017-08-02 17:23:14 writer:pprp 题意:将n分解为n/2, n%2, n/2三部分,再将n/2分解..得到一个序列只有0和1,给出[l, r]问l到r有几个1 题解:分治 ...
- B. Code For 1 分治
time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standa ...
- BZOJ 2244: [SDOI2011]拦截导弹 (CDQ分治 三维偏序 DP)
题意 略- 分析 就是求最长不上升子序列,坐标取一下反就是求最长不下降子序列,比较大小是二维(h,v)(h,v)(h,v)的比较.我们不看概率,先看第一问怎么求最长不降子序列.设f[i]f[i]f[i ...
- Codeforces 768B - Code For 1(分治思想)
768B - Code For 1 思路:类似于线段树的区间查询. 代码: #include<bits/stdc++.h> using namespace std; #define ll ...
- Code Chef TSUM2(动态凸包+点分治)
题面 传送门 题解 真是毒瘤随机化算法居然一分都不给 首先这种树上的题目一般想到的都是点分 我们考虑如何统计经过当前点的路径的贡献,设当前点\(u\)在序列中是第\(c\)个,那么一条路径的贡献就是 ...
- HDU5618 & CDQ分治
Description: 三维数点 Solution: 第一道cdq分治...感觉还是很显然的虽然题目不能再傻逼了... Code: /*=============================== ...
- 【Codeforces715C&716E】Digit Tree 数学 + 点分治
C. Digit Tree time limit per test:3 seconds memory limit per test:256 megabytes input:standard input ...
- 【BZOJ-4456】旅行者 分治 + 最短路
4456: [Zjoi2016]旅行者 Time Limit: 20 Sec Memory Limit: 512 MBSubmit: 254 Solved: 162[Submit][Status] ...
随机推荐
- SilverLight: 数据绑定(1)-绑定到数据对象
ylbtech-SilverLight-DataBinding: Binding to Data Objects(绑定到数据对象) 1.A, Building a Data Object(创建一个数 ...
- hadoop学习笔记——环境搭建
基础环境准备: 系统:(VirtualBox) ubuntu-12.04.2-desktop-i386.iso hadoop版本:hadoop-0.20.203.0rc1.tar.gz jdk版本:j ...
- 修改 本地 IP 及 正则表达式 test exec match 的区别
修改 IP 1.打开 "打开网络和共享中心" 2.打开 "更改适配器设置" 3.打开 "本地连接" 属性 4.修改 "协议版本 4 ...
- Java如何Attachment源码
该文章教你如何在Eclipse中Attachment源码,学到了不少东西. http://jingyan.baidu.com/article/1709ad80b107f64635c4f040.html ...
- swift学习_xcode6搭建
首先是环境搭建 , 我的是苹果系统 , 我是个穷小子. 8k的电脑离我比較遥远. 自己动手的黑苹果 . 总价1k, 学习够用了即可.期间也学到了非常多东西 . 就是穷人仅仅能发时间去换钱了, 一直在考 ...
- android自己定义渐变进度条
项目中须要用到一个弧形渐变的进度条,通过android自带是不能实现的.我是没有找到实现的方法,有大神知道的能够指点.效果图是以下这种 这是通过继承VIew来绘制出来的,网上也有相似的,可是代码那是相 ...
- kubectl技巧之查看资源列表,资源版本和资源schema配置
系列目录 在kubernetes里,pod,service,rs,rc,deploy,resource等对象都需要使用yaml文件来创建,很多时候我们都是参照照官方示例或者一些第三方示例来编写yaml ...
- longestIncreasingSequence最长上升子序列问题
package dp; /** * 最长上升子序列问题 */ public class LongestIncreasingSubsequence { /** * 原始dp * @param arr * ...
- Html5的placeholder属性(IE兼容)
HTML5对Web Form做了很多增强,比方input新增的type类型.Form Validation等. Placeholder是HTML5新增的还有一个属性,当input或者textarea设 ...
- Hadoop - YARN 概述
一 概述 Apache Hadoop YARN (Yet Another Resource Negotiator,还有一种资源协调者)是一种新的 Hadoop 资源管理器,它是一个通用资源 ...