【BZOJ1672】[Usaco2005 Dec]Cleaning Shifts 清理牛棚 动态规划
【BZOJ1672】[Usaco2005 Dec]Cleaning Shifts
Description
Farmer John's cows, pampered since birth, have reached new heights of fastidiousness. They now require their barn to be immaculate. Farmer John, the most obliging of farmers, has no choice but hire some of the cows to clean the barn. Farmer John has N (1 <= N <= 10,000) cows who are willing to do some cleaning. Because dust falls continuously, the cows require that the farm be continuously cleaned during the workday, which runs from second number M to second number E during the day (0 <= M <= E <= 86,399). Note that the total number of seconds during which cleaning is to take place is E-M+1. During any given second M..E, at least one cow must be cleaning. Each cow has submitted a job application indicating her willingness to work during a certain interval T1..T2 (where M <= T1 <= T2 <= E) for a certain salary of S (where 0 <= S <= 500,000). Note that a cow who indicated the interval 10..20 would work for 11 seconds, not 10. Farmer John must either accept or reject each individual application; he may NOT ask a cow to work only a fraction of the time it indicated and receive a corresponding fraction of the salary. Find a schedule in which every second of the workday is covered by at least one cow and which minimizes the total salary that goes to the cows.
Input
* Line 1: Three space-separated integers: N, M, and E. * Lines 2..N+1: Line i+1 describes cow i's schedule with three space-separated integers: T1, T2, and S.
Output
* Line 1: a single integer that is either the minimum total salary to get the barn cleaned or else -1 if it is impossible to clean the barn.
Sample Input
0 2 3
3 4 2
0 0 1
FJ has three cows, and the barn needs to be cleaned from second 0 to second
4. The first cow is willing to work during seconds 0, 1, and 2 for a total
salary of 3, etc.
Sample Output
HINT
约翰有3头牛,牛棚在第0秒到第4秒之间需要打扫.第1头牛想要在第0,1,2秒内工作,为此她要求的报酬是3美元.其余的依此类推. 约翰雇佣前两头牛清扫牛棚,可以只花5美元就完成一整天的清扫.
题解:完了,被水题伤害了,原本想用线段树,结果狂WA不止,后来看题解n^2动规就过了,给跪了。
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#define lson x<<1
#define rson x<<1|1
using namespace std;
int n,m,e;
long long ans;
struct cows
{
int t1,t2;
long long c;
}p[10010];
long long f[10010];
bool cmp(cows a,cows b)
{
return a.t2<b.t2;
}
int main()
{
int i,j;
scanf("%d%d%d",&n,&m,&e);
for(i=1;i<=n;i++) scanf("%d%d%lld",&p[i].t1,&p[i].t2,&p[i].c);
sort(p+1,p+n+1,cmp);
memset(f,0x3f,sizeof(f));
ans=f[0];
for(i=1;i<=n;i++)
{
if(p[i].t1==m)
{
f[i]=p[i].c;
continue;
}
for(j=i-1;p[j].t2>=p[i].t1-1&&j>=1;j--)
f[i]=min(f[i],p[i].c+f[j]);
if(p[i].t2==e)
ans=min(ans,f[i]);
}
if(ans==f[0])
printf("-1");
else
printf("%lld",ans);
return 0;
}
【BZOJ1672】[Usaco2005 Dec]Cleaning Shifts 清理牛棚 动态规划的更多相关文章
- BZOJ1672: [Usaco2005 Dec]Cleaning Shifts 清理牛棚
1672: [Usaco2005 Dec]Cleaning Shifts 清理牛棚 Time Limit: 5 Sec Memory Limit: 64 MBSubmit: 414 Solved: ...
- [BZOJ1672][Usaco2005 Dec]Cleaning Shifts 清理牛棚 线段树优化DP
链接 题意:给你一些区间,每个区间都有一个花费,求覆盖区间 \([S,T]\) 的最小花费 题解 先将区间排序 设 \(f[i]\) 表示决策到第 \(i\) 个区间,覆盖满 \(S\dots R[i ...
- BZOJ_1672_[Usaco2005 Dec]Cleaning Shifts 清理牛棚_动态规划+线段树
BZOJ_1672_[Usaco2005 Dec]Cleaning Shifts 清理牛棚_动态规划+线段树 题意: 约翰的奶牛们从小娇生惯养,她们无法容忍牛棚里的任何脏东西.约翰发现,如果要使这群 ...
- BZOJ 1672: [Usaco2005 Dec]Cleaning Shifts 清理牛棚
题目 1672: [Usaco2005 Dec]Cleaning Shifts 清理牛棚 Time Limit: 5 Sec Memory Limit: 64 MB Description Farm ...
- P4644 [Usaco2005 Dec]Cleaning Shifts 清理牛棚
P4644 [Usaco2005 Dec]Cleaning Shifts 清理牛棚 你有一段区间需要被覆盖(长度 <= 86,399) 现有 \(n \leq 10000\) 段小线段, 每段可 ...
- [Usaco2005 Dec]Cleaning Shifts 清理牛棚 (DP优化/线段树)
[Usaco2005 Dec] Cleaning Shifts 清理牛棚 题目描述 Farmer John's cows, pampered since birth, have reached new ...
- 洛谷P4644 [USACO2005 Dec]Cleaning Shifts 清理牛棚 [DP,数据结构优化]
题目传送门 清理牛棚 题目描述 Farmer John's cows, pampered since birth, have reached new heights of fastidiousness ...
- 【bzoj1672】[USACO2005 Dec]Cleaning Shifts 清理牛棚
题目描述 Farmer John's cows, pampered since birth, have reached new heights of fastidiousness. They now ...
- 【bzoj1672】[USACO2005 Dec]Cleaning Shifts 清理牛棚 dp/线段树
题目描述 Farmer John's cows, pampered since birth, have reached new heights of fastidiousness. They now ...
随机推荐
- SQLServer2000数据库的安装
==================. 未完待续,持续更新中... -------------------------------------------------
- thinkphp 后台权限列表
核心代码: // 检测用户权限权限 public function admin_priv($action){ $action_list = session('user.action_list'); i ...
- 暴力枚举N级子域名
#!/usr/bin/env python# -*- encoding: utf-8 -*-# A simple and fast sub domains brute tool for pentest ...
- Druid初步学习
Druid是一个JDBC组件,它包括三部分: DruidDriver 代理Driver,能够提供基于Filter-Chain模式的插件体系. DruidDataSource 高效可管理的数据库连接池 ...
- MySQL检查重复索引工具-pt-duplicate-key-checker
在MySQL中是允许在同一个列上创建多个索引的,示例如下: mysql --socket=/tmp/mysql5173.sock -uroot -p mysql> SELECT VERSION( ...
- JVM参数OmitStackTraceInFastThrow:不打印NullPointerException异常堆栈
查看线上日志,遇到一个诡异的问题,就是系统大量空指针的异常,但是没有打印堆栈,导致不方便定位问题. 经过一番代码调试,确定并非程序代码问题.没有线索之后,从Google找到了答案:是因为在server ...
- MySQL索引的设计和使用
一.索引可以有效地提升SELECT操作的性能,同时会影响UPDATE.CREATE和DELETE操作的性能.每种引擎对于表的索引有数量和长度的限制. 二.索引的设计原则 (A) 搜索的索引列,不一定是 ...
- matlab GUI封装exe文件
学习matlab过程中,有时有些程序处理数据时老是看着代码,也会觉得疲倦,那么要试一试matlab的GUI吗?我就是这么使用matlab的GUI制作一个小程序,并且使用matlab封装成了exe文件. ...
- jython安装与配置
安装jython 0. 计算机中要安装jdk 1. 在官网www.jython.org上找到下载页面,然后下载jython-installe 2. 在cmd.exe中运行java -jar jytho ...
- 学习 CSS 样式
1.CSS浮动 : http://www.cnblogs.com/zhongxinWang/archive/2013/03/27/2984764.html (1)一个重要结论: ...