hdu 2955 Robberies (01背包好题)
Robberies
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 31769 Accepted Submission(s): 11527
For a few months now, Roy has been assessing the security of various banks and the amount of cash they hold. He wants to make a calculated risk, and grab as much money as possible.
His mother, Ola, has decided upon a tolerable probability of getting caught. She feels that he is safe enough if the banks he robs together give a probability less than this.
Bank j contains Mj millions, and the probability of getting caught from robbing it is Pj .
Notes and Constraints
0 < T <= 100
0.0 <= P <= 1.0
0 < N <= 100
0 < Mj <= 100
0.0 <= Pj <= 1.0
A bank goes bankrupt if it is robbed, and you may assume that all probabilities are independent as the police have very low funds.
0.04 3
1 0.02
2 0.03
3 0.05
0.06 3
2 0.03
2 0.03
3 0.05
0.10 3
1 0.03
2 0.02
3 0.05
题目大意:
Roy是一个盗贼。现在有n个银行成了他的下手目标。对第i个银行下手,他会获得mi元钱,同时有pi的概率被抓。问在被抓概率不超过p的情况下,他最多能得到多少钱。
01背包好题。
这题仔细想想还是很有趣的。获得的钱其实是背包容量。获得这些钱安全的概率才是dp存储的东西。要好好想想。
此外,对double类型变量输入输出是 printf&%f scanf&%lf,注意。
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<queue>
#include<stack> using namespace std; const int maxn=; int money[maxn+];
double safe[maxn+];//不被抓的概率作为重量
double dp[maxn*maxn+];//获得i钱,不被抓的概率 int main()
{
int t;
scanf("%d",&t);
while(t--)
{
double p;int n;
scanf("%lf%d",&p,&n);
p=-p;
int sum=;//最多获得多少钱
for(int i=;i<=n;i++)
{
scanf("%d%lf",money+i,safe+i);
safe[i]=-safe[i];
sum+=money[i];
} for(int i=;i<=sum;i++)
dp[i]=;
dp[]=;
for(int i=;i<=n;i++)
{
for(int j=sum;j>=money[i];j--)
{
dp[j]=max(dp[j],dp[j-money[i]]*safe[i]);
}
} for(int i=sum;i>=;i--)
if(dp[i]>p)
{
printf("%d\n",i);
break;
}
}
return ;
}
hdu 2955 Robberies (01背包好题)的更多相关文章
- hdu 2955 Robberies (01背包)
链接:http://acm.hdu.edu.cn/showproblem.php?pid=2955 思路:一开始看急了,以为概率是直接相加的,wa了无数发,这道题目给的是被抓的概率,我们应该先求出总的 ...
- HDU 2955 Robberies(01背包变形)
Robberies Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total S ...
- hdu 2955 Robberies 0-1背包/概率初始化
/*Robberies Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total S ...
- HDU——2955 Robberies (0-1背包)
题意:有N个银行,每抢一个银行,可以获得\(v_i\)的前,但是会有\(p_i\)的概率被抓.现在要把被抓概率控制在\(P\)之下,求最多能抢到多少钱. 分析:0-1背包的变形,把重量变成了概率,因为 ...
- HDU 2955 Robberies --01背包变形
这题有些巧妙,看了别人的题解才知道做的. 因为按常规思路的话,背包容量为浮点数,,不好存储,且不能直接相加,所以换一种思路,将背包容量与价值互换,即令各银行总值为背包容量,逃跑概率(1-P)为价值,即 ...
- HDU 2955 Robberies(01背包)
Robberies Problem Description The aspiring Roy the Robber has seen a lot of American movies, and kno ...
- Jam's balance HDU - 5616 (01背包基础题)
Jim has a balance and N weights. (1≤N≤20) The balance can only tell whether things on different side ...
- HDU 2955 【01背包/小数/概率DP】
Robberies Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Sub ...
- HDOJ 2955 Robberies (01背包)
10397780 2014-03-26 00:13:51 Accepted 2955 46MS 480K 676 B C++ 泽泽 http://acm.hdu.edu.cn/showproblem. ...
随机推荐
- Java内存模型与volatile关键字
Java内存模型与volatile关键字 一).并发程序开发 并行程序的开发要涉及多线程.多任务间的协作和数据共享问题. 常用的并发控制:内部锁.重入锁.读写锁.信号量. 二).线程的特点 线程的特点 ...
- web前端开发面试题(Vue.js)
1.active-class是哪个组件的属性?嵌套路由怎么定义? 答:vue-router模块的router-link组件. 2.怎么定义vue-router的动态路由?怎么获取传过来的动态参数? ...
- 2019-10-9:渗透测试,基础学习the-backdoor-factory-master(后门工厂)初接触
该文章仅供学习,利用方法来自网络文章,仅供参考 the-backdoor-factory-master(后门工制造厂)原理:可执行二进制文件中有大量的00,这些00是不包含数据的,将这些数据替换成pa ...
- day 27 网路编程 面向对象多继承
知识补充: 字符串转化为字节 string1 = input(“请输入你的名字”) string1.encode('utf-8') 字节转化为字符串 byte1 = b"alex" ...
- Crontab爬虫定时执行
- Xamarin.Forms 学习系列之优秀UI收集
1.各种优秀UI例子 https://github.com/jsuarezruiz/xamarin-forms-goodlooking-UI 输入框例子 https://github.com/enis ...
- LESSON 3- Discrete Memory-less Sources
1. Entropy H[X] - bounds on Lmin 2. Huffman’s algorithm for optimal source code
- 如何优雅地在Stack Overflow提问?
今天来给大家聊一聊 Stack Overflow,Stack Overflow 是什么呢? 什么是 Stack Overflow? Stack Overflow 是一个全球最大的技术问答网站,作为一个 ...
- 英语口语考试资料Language learning
"Learning a language is easy. Even a child can do it!" Most adults who are learning a seco ...
- Chapter 07-Basic statistics(Part2 Frequency and contingency tables)
这一部分使用在vcd包中的Arthritis数据集. > library(vcd) 载入需要的程辑包:MASS 载入需要的程辑包:grid 载入需要的程辑包:colorspace > he ...