arc 097 E - Sorted and Sorted
E - Sorted and Sorted
Time limit : 2sec / Memory limit : 1024MB
Score : 600 points
Problem Statement
There are 2N balls, N white and N black, arranged in a row. The integers from 1 through N are written on the white balls, one on each ball, and they are also written on the black balls, one on each ball. The integer written on the i-th ball from the left (1 ≤ i ≤ 2N) is ai, and the color of this ball is represented by a letter ci. ci = W
represents the ball is white; ci = B
represents the ball is black.
Takahashi the human wants to achieve the following objective:
- For every pair of integers (i,j) such that 1 ≤ i < j ≤ N, the white ball with i written on it is to the left of the white ball with j written on it.
- For every pair of integers (i,j) such that 1 ≤ i < j ≤ N, the black ball with i written on it is to the left of the black ball with j written on it.
In order to achieve this, he can perform the following operation:
- Swap two adjacent balls.
Find the minimum number of operations required to achieve the objective.
Constraints
- 1 ≤ N ≤ 2000
- 1 ≤ ai ≤ N
- ci =
W
or ci =B
. - If i ≠ j, (ai,ci) ≠ (aj,cj).
Input
Input is given from Standard Input in the following format:
N
c1 a1
c2 a2
:
c2N a2N
Output
Print the minimum number of operations required to achieve the objective.
Sample Input 1
3
B 1
W 2
B 3
W 1
W 3
B 2
Sample Output 1
4
The objective can be achieved in four operations, for example, as follows:
- Swap the black 3 and white 1.
- Swap the white 1 and white 2.
- Swap the black 3 and white 3.
- Swap the black 3 and black 2.
Sample Input 2
4
B 4
W 4
B 3
W 3
B 2
W 2
B 1
W 1
Sample Output 2
18
Sample Input 3
9
W 3
B 1
B 4
W 1
B 5
W 9
W 2
B 6
W 5
B 3
W 8
B 9
W 7
B 2
B 8
W 4
W 6
B 7
Sample Output 3
41
https://arc097.contest.atcoder.jp/tasks/arc097_c
dp[i][j]表示前(i + j)个有 i 个白的,j 个黑的,都已经排好序的代价
dpi,j = min(dp[ i − 1 ][ j ] + cost,dp[ i ][ j - 1 ] + cost)
cost是原来位置移到第(i + j)个的代价,即这段中的逆序对个数,树状数组维护即可
#include<bits/stdc++.h>
typedef long long ll ;
#define rep(i, a, b) for (int i = a; i <= b; ++i)
using namespace std; const int MAXN = ;
const ll INF = 2e9;
int n;
int dp[MAXN][MAXN];
int a[MAXN + MAXN], c[MAXN + MAXN];
int p1[MAXN], p0[MAXN];
int t[MAXN + MAXN]; void add (int k, int d) { while (k <= n + n) { t[k] += d; k += k & -k; } }
int sum (int k) { int s = ; while (k > ) { s += t[k]; k -= k & -k; } return s; } int main() {
cin >> n;
rep(i, , n + n) {
char ch;
cin >> ch >> a[i];
if (ch == 'W') {
p0[a[i]] = i;
c[i] = ;
}
else {
p1[a[i]] = i;
c[i] = ;
}
add(i, );
}
p1[] = n + n + ;
p0[] = n + n + ;
dp[][] = ;
rep(j, , n) {
add(p1[j], -);
dp[][j] = dp[][j - ] + sum(p1[j] - );
}
rep(j, , n) add(p1[j], );
rep(i, , n) {
add(p0[i], -);
rep(j, , n) {
add(p1[j], -);
dp[i][j] = INF;
if (i) dp[i][j] = min(dp[i][j], dp[i - ][j] + sum(p0[i] - ));
if (j) dp[i][j] = min(dp[i][j], dp[i][j - ] + sum(p1[j] - ));
}
rep(j, , n) add(p1[j], );
}
cout << dp[n][n] << "\n";
return ;
}
arc 097 E - Sorted and Sorted的更多相关文章
- python中sorted和.sorted 、reversed和reverse的注意点
L=[1,2,3,4]l1=[123,123,23]if l1.sort() == L.reverse(): #这个判断式是恒等的,因为两个函数的返回值都是None(其实是无返回值) pri ...
- 【AtCoder】 ARC 097
link C-K-th Substring 题意:找出已知串中第\(k\)大的子串,子串相同的不算 \(k\)好小啊,要怎么做啊 不是[Tjoi2015]弦论吗 算了,直接SAM吧 #include& ...
- python中sorted和sorted 、reversed和reverse的使用。
#encoding = utf-8 list = [1,8,3,6] print(list.sort()) #None print(list) #[1,3,6,8] print(sorted(list ...
- AtCoder ARC097C Sorted and Sorted:dp
传送门 题意 有 $ 2n $ 个球排成一行,其中恰好有 $ n $ 个白球和 $ n $ 个黑球.每个球上写着数字,其中白球上的数字的并集为 $ \lbrace 1 \dots n\rbrace $ ...
- ARC097E Sorted and Sorted
传送门 题目 There are 2N balls, N white and N black, arranged in a row. The integers from 1 through N are ...
- python 中 sorted() 和 list.sort() 的用法
今天用python自带的sorted对一个列表进行排序, 在这里总结一下 只要是可迭代对象都可以用sorted . sorted(itrearble, cmp=None, key=None, reve ...
- python 排序sorted
num = [3,2,4,6,5] anum = sorted(num) dnum = sorted(num,reverse=True) print '升序:',anum # 升序: [2, 3, 4 ...
- Redis in .NET Core 入门:(5) Sorted SET
第1篇:https://www.cnblogs.com/cgzl/p/10294175.html 第2篇 String:https://www.cnblogs.com/cgzl/p/10297565. ...
- Redis实战 - 2.list、set和Sorted Set
List Redis的List是通过Linked List(链表)来实现的String集合,所以插入数据的速度很快. 但是缺点就是在数据量比较大的时候,访问某个数据的时间可能会很长,但针对这种情况,可 ...
随机推荐
- Favorite Donut(HDU 5442)最小表示法+二分
题目给出一个字符串,由a~z表示甜度,随字典序增大,字符串首尾相连形成一个圈,要求从一个位置开始字典序最大的字符串,输出位置以及是顺时针还是逆时针表示.顺时针用0表示,逆时针用1表示. 此题只需要查找 ...
- 使用JBolt新建Maven版工程步骤
一.打开新建对话框 在左侧右键new中可以找到JFinal创建工程的菜单 JBoltHome页面也有快捷按钮用来弹出创建工程对话框. 二.填写Maven和其他信息配置 填写工程name 主包名 下面有 ...
- 《DSP using MATLAB》Problem 7.14
代码: %% ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ %% Output In ...
- Hello_World
简单A+B #include <stdio> int main() { int a,b; scanf("%d%d",&a, &b); printf(&q ...
- Python安装及IDE激活
简介: Windows10下安装激活Pycharm,并同时安装Python 3.x.2.x,便于在Pycharm开发环境中使用不同版本的解释器进行对比学习. 目录: 一.Python 3.x安装 二. ...
- 新手入门HTML5有什么推荐的书籍?
很多想迈入HTML5开发行列的人,都会问一个问题:要成为一个更好的开发人员,我应该读哪些书?有哪些HTML5开发的书籍推荐吗? 有人说开卷有益,读万卷书行万里路;有人说,书不在多,精益求精;有人说,书 ...
- express中遇到的一个小问题“403”
这样子的一个express简单项目文件执行会出现403 Forbidden的错误: var express = require('express'); var app = express(); app ...
- php7 pdo抽象类操作数据库
查询 <?php try { $dbconnect = new PDO('mysql:host=localhost;dbname=pdodatabase','root','753951'); } ...
- Sql Server查看死锁及堵塞脚本
--每秒死锁数量 SELECT * FROM sys.dm_os_performance_counters WHERE counter_name LIKE 'Number of Deadlocksc% ...
- Eureka入门案例
1.整体思路 1.1.服务注册中心Eureka(可以是一个集群,对外暴露自己的地址) 1.2.服务提供者:启动后向Eureka注册自己的信息(地址,提供什么服务) 1.3.客户端消费者:向Eureka ...