codeforces 414C C. Mashmokh and Reverse Operation(归并排序求逆序对)
题目链接:
C. Mashmokh and Reverse Operation
4 seconds
512 megabytes
standard input
standard output
Mashmokh's boss, Bimokh, didn't like Mashmokh. So he fired him. Mashmokh decided to go to university and participate in ACM instead of finding a new job. He wants to become a member of Bamokh's team. In order to join he was given some programming tasks and one week to solve them. Mashmokh is not a very experienced programmer. Actually he is not a programmer at all. So he wasn't able to solve them. That's why he asked you to help him with these tasks. One of these tasks is the following.
You have an array a of length 2n and m queries on it. The i-th query is described by an integer qi. In order to perform the i-th query you must:
- split the array into 2n - qi parts, where each part is a subarray consisting of 2qi numbers; the j-th subarray (1 ≤ j ≤ 2n - qi) should contain the elements a[(j - 1)·2qi + 1], a[(j - 1)·2qi + 2], ..., a[(j - 1)·2qi + 2qi];
- reverse each of the subarrays;
- join them into a single array in the same order (this array becomes new array a);
- output the number of inversions in the new a.
Given initial array a and all the queries. Answer all the queries. Please, note that the changes from some query is saved for further queries.
The first line of input contains a single integer n (0 ≤ n ≤ 20).
The second line of input contains 2n space-separated integers a[1], a[2], ..., a[2n] (1 ≤ a[i] ≤ 109), the initial array.
The third line of input contains a single integer m (1 ≤ m ≤ 106).
The fourth line of input contains m space-separated integers q1, q2, ..., qm (0 ≤ qi ≤ n), the queries.
Note: since the size of the input and output could be very large, don't use slow output techniques in your language. For example, do not use input and output streams (cin, cout) in C++.
Output m lines. In the i-th line print the answer (the number of inversions) for the i-th query.
2
2 1 4 3
4
1 2 0 2
0
6
6
0
1
1 2
3
0 1 1
0
1
0
If we reverse an array x[1], x[2], ..., x[n] it becomes new array y[1], y[2], ..., y[n], where y[i] = x[n - i + 1] for each i.
The number of inversions of an array x[1], x[2], ..., x[n] is the number of pairs of indices i, j such that: i < j and x[i] > x[j].
题意:
问2^n个数进行如题的操作每次操作后逆序对是多少;
思路:
像归并排序那样先划分,然后再求出每个划分里面的逆序对,合并后再求两个区间之间的逆序对,倒序把逆序对和正序对的数目交换了;
最近抄代码抄的厉害,哎;
AC代码:
#include <bits/stdc++.h>
using namespace std;
#define Riep(n) for(int i=1;i<=n;i++)
#define Riop(n) for(int i=0;i<n;i++)
#define Rjep(n) for(int j=1;j<=n;j++)
#define Rjop(n) for(int j=0;j<n;j++)
#define mst(ss,b) memset(ss,b,sizeof(ss));
typedef long long LL;
const LL mod=1e9+;
const double PI=acos(-1.0);
const int inf=0x3f3f3f3f;
const int N=1e6+5e5;
LL sum[][];
int n,a[<<];
void dfs(int l,int r,int deep)
{
if(l>=r)return ;
int mid=(l+r)>>;
dfs(l,mid,deep-);
dfs(mid+,r,deep-);
for(int i=l;i<=mid;i++)
{ int temp=lower_bound(a+mid+,a+r+,a[i])-(a+mid+);
sum[deep][]+=(LL)temp;
temp=r-mid-(upper_bound(a+mid+,a+r+,a[i])-(a+mid+));
sum[deep][]+=(LL)temp;
}
sort(a+l,a+r+);
}
int main()
{
scanf("%d",&n);
int y=(<<n);
Riep(y)scanf("%d",a+i);
dfs(,y,n);
int q,x;
scanf("%d",&q);
while(q--)
{
scanf("%d",&x);
while(x)
{
swap(sum[x][],sum[x][]);
x--;
}
LL ans=;
Riep(n)ans+=sum[i][];
printf("%I64d\n",ans);
}
return ;
}
codeforces 414C C. Mashmokh and Reverse Operation(归并排序求逆序对)的更多相关文章
- 2014 HDU多校弟五场A题 【归并排序求逆序对】
这题是2Y,第一次WA贡献给了没有long long 的答案QAQ 题意不难理解,解题方法不难. 先用归并排序求出原串中逆序对的个数然后拿来减去k即可,如果答案小于0,则取0 学习了归并排序求逆序对的 ...
- 归并排序&&归并排序求逆序对
归并排序 归并排序(MERGE-SORT)是建立在归并操作上的一种有效的排序算法,该算法是采用分治法(Divide and Conquer)的一个非常典型的应用.将已有序的子序列合并,得到完全有序的序 ...
- 【BZOJ4769】超级贞鱼 归并排序求逆序对
[BZOJ4769]超级贞鱼 Description 马达加斯加贞鱼是一种神奇的双脚贞鱼,它们把自己的智慧写在脚上——每只贞鱼的左脚和右脚上各有一个数.有一天,K只贞鱼兴致来潮,排成一列,从左到右第i ...
- poj2299(归并排序求逆序对)
题目链接:https://vjudge.net/problem/POJ-2299 题意:给定一个序列,每次只能交换邻近的两个元素,问要交换多少次才能使序列按升序排列. 思路:本质就是求逆序对.我们用归 ...
- 归并排序+归并排序求逆序对(例题P1908)
归并排序(merge sort) 顾名思义,这是一种排序算法,时间复杂度为O(nlogn),时间复杂度上和快排一样 归并排序是分治思想的应用,我们先将n个数不断地二分,最后得到n个长度为1的区间,显然 ...
- 归并排序求逆序对(poj 2299)
归并排序求逆序对 题目大意 给你多个序列,让你求出每个序列中逆序对的数量. 输入:每组数据以一个数 n 开头,以下n行,每行一个数字,代表这个序列: 输出:对于输出对应该组数据的逆序对的数量: 顺便在 ...
- HDU 3743 Frosh Week(归并排序求逆序对)
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3743 题目意思就是给你一个长为n的序列,让你求逆序对.我用的是归并排序来求的.归并排序有一个合并的过程 ...
- 浙江工商大学15年校赛I题 Inversion 【归并排序求逆序对】
Inversion Time Limit 1s Memory Limit 131072KB Judge Program Standard Ratio(Solve/Submit) 15.00%(3/20 ...
- 归并排序(归并排序求逆序对数)--16--归并排序--Leetcode面试题51.数组中的逆序对
面试题51. 数组中的逆序对 在数组中的两个数字,如果前面一个数字大于后面的数字,则这两个数字组成一个逆序对.输入一个数组,求出这个数组中的逆序对的总数. 示例 1: 输入: [7,5,6,4] 输出 ...
随机推荐
- npm start 修改启动端口的不同方式
antd的启动配置文件基于package.json文件,配合roadhog使用时,启动配置是: "scripts": { "start": "road ...
- 51 NOD 1383 整数分解为2的幂
设f[i]为i这个数的划分方案,则: 1.i是奇数的时候,最前面只能放1,所以f[i] = f[i-1] 2.i是偶数的时候,最前面可以放1也可以不放1,而不放1的时候数列都是偶数所以 f[i] = ...
- SQL Server 存储字符数较大字段的问题
SQL Server 2000专门提供了处理text,ntext,image字段的函数,他们是: TEXTPTR TEXTVALID READTEXT UPDATETEXT WRITETEXT 一般作 ...
- 【Gradle】配置中引用的jar包版本后面自动加冒号导致引入jar包失败的问题/gradle中引用jar包版本不一致的问题/gradle中引用jar失败的问题 解决方法
idea中 gradle中 引用jar包,版本后面默认加:的问题 gradle中引用jar包版本不一致的问题 gradle中引用jar失败的问题 如上题目所示,三个问题其实都是同一样的简单又恶心,因为 ...
- springboot mybatis 项目框架源码 shiro 集成代码生成器 ehcache缓存
1.代码生成器: [正反双向](单表.主表.明细表.树形表,快速开发利器)freemaker模版技术 ,0个代码不用写,生成完整的一个模块,带页面.建表sql脚本.处理类.service等完整模块2. ...
- python 3.4读取输入参数
python 3.4读取输入参数 学习了:https://blog.csdn.net/qq_24815615/article/details/52302615 注意,sys.args[0]是pytho ...
- Git的使用 -- 用git玩翻github,结尾有惊喜!有惊喜!有惊喜!林妙妙看了说:牛呲呼啦带闪电 (三)(超详解)
简介 上一篇主要讲解的是Git安装及配置,这一篇就详细的从无到有的来用Git玩翻github. 一.什么是Github Github是全球最大的社交编程及代码托管网站(https://github.c ...
- register_shutdown_function函数详解
设定错误和异常处理三函数 register_shutdown_function(array(‘Debug’,'fatalError’)); //定义PHP程序执行完成后执行的函数 set_error_ ...
- HDU 4334 Trouble(哈希|线性查找)
给定五个集合.问是否能从五个集合各取一个元素,使得元素之和为0. 这道题有两种做法,一种是哈希,然而之前没写过哈希.....比赛后从大神那copy了一份. 这里说还有一种. 对于这五个集合分为三组.1 ...
- 关于MP4视频拖动的原理与分析(一)
本来想说说关于mp4和一些常见视频文件格式方面的历史. 如今想想没啥必要.毕竟本文是在讲关于mp4点播拖动方面的技术细节. 绪论,前言神马的显得有点多余. 说起MP4.不得不提"Digita ...