POJ2184(01背包变形)
Time Limit: 1000MS | Memory Limit: 65536K | |
Total Submissions: 11092 | Accepted: 4404 |
Description
fun..."
- Cows with Guns by Dana Lyons
The cows want to prove to the public that they are both smart and fun. In order to do this, Bessie has organized an exhibition that will be put on by the cows. She has given each of the N (1 <= N <= 100) cows a thorough interview and determined two values for each cow: the smartness Si (-1000 <= Si <= 1000) of the cow and the funness Fi (-1000 <= Fi <= 1000) of the cow.
Bessie must choose which cows she wants to bring to her exhibition. She believes that the total smartness TS of the group is the sum of the Si's and, likewise, the total funness TF of the group is the sum of the Fi's. Bessie wants to maximize the sum of TS and TF, but she also wants both of these values to be non-negative (since she must also show that the cows are well-rounded; a negative TS or TF would ruin this). Help Bessie maximize the sum of TS and TF without letting either of these values become negative.
Input
* Lines 2..N+1: Two space-separated integers Si and Fi, respectively the smartness and funness for each cow.
Output
Sample Input
5
-5 7
8 -6
6 -3
2 1
-8 -5
Sample Output
8
题意:给出n个奶牛,每个奶牛有ts之和tf值,从中选出一些奶牛使ts+tf之和最大且ts之和与tf之和均非负.
思路:选与不选的问题,转化为01背包。将ts作为体积,tf作为价值。
#include"cstdio"
#include"cstring"
#include"algorithm"
using namespace std;
const int MAXN=;
const int INF=0x3fffffff;
int dp[MAXN];
int n;
int ts[MAXN],tf[MAXN];
int main()
{
while(scanf("%d",&n)!=EOF)
{
for(int i=;i<MAXN;i++) dp[i]=-INF;
for(int i=;i<n;i++)
{
scanf("%d%d",&ts[i],&tf[i]);
}
dp[]=;
for(int i=;i<n;i++)
{
if(ts[i]<&&tf[i]<) continue;
if(ts[i]>)
{
for(int j=;j>=ts[i];j--)//体积大于0时倒序
dp[j]=max(dp[j],dp[j-ts[i]]+tf[i]);
}
else
{
for(int j=;j<=+ts[i];j++)//体积小于0时正序
dp[j]=max(dp[j],dp[j-ts[i]]+tf[i]);
}
}
int maxn=-INF;
for(int i=;i<=;i++)
{
if(dp[i]>=)
maxn=max(maxn,dp[i]+i-);
} if(maxn>) printf("%d\n",maxn);
else printf("0\n"); } return ;
}
最新文章
- ADO.NET 中的新增功能
- 将string转换成char* (转)
- SSH 框架
- missing sdkl in .NET Core 1.0.1 - VS 2015 Tooling Preview 2
- Best Time to Buy and Sell Stock II [LeetCode]
- css背景定位
- Hibernate从入门到精通(十)多对多单向关联映射
- java图片处理
- vs2010 和 svn的结合运用,svn的安装
- MVC小系列(二十一)【带扩展名的路由可能失效】
- .Net Mvc4 Kendo Grid Demo
- (中等) POJ 2991 Crane , 几何+线段树。
- python入门小记
- PHP——isset和empty
- [SHOI2014]三叉神经树
- MYSQL常用命令2
- [C#]位运算符
- Spring.xml中配置注解context:annotation-config和context:component-scan简述
- CSS Grid 读书笔记
- centos7虚拟机安装elasticsearch5.0.x-安装篇