Light Bulb(三分)
Time Limit: 1 Second Memory Limit: 32768 KB
Compared to wildleopard's wealthiness, his brother mildleopard is rather poor. His house is narrow and he has only one light bulb in his house. Every night, he is wandering in his incommodious house, thinking of how to earn more money. One day, he found that the length of his shadow was changing from time to time while walking between the light bulb and the wall of his house. A sudden thought ran through his mind and he wanted to know the maximum length of his shadow.
Input
The first line of the input contains an integer T (T <= 100), indicating the number of cases.
Each test case contains three real numbers H, h and D in one line. H is the height of the light bulb while h is the height of mildleopard. D is distance between the light bulb and the wall. All numbers are in range from 10-2 to 103, both inclusive, and H - h >= 10-2.
Output
For each test case, output the maximum length of mildleopard's shadow in one line, accurate up to three decimal places..
Sample Input
3
2 1 0.5
2 0.5 3
4 3 4
Sample Output
1.000
0.750
4.000
题解:找出函数,两种方法,一种求导直接求,另一种是三分;
#include<stdio.h>
#include<math.h>
int main(){
int T;
double H,h,D;
//公式:D-x+H-(H-h)*D/x;
//求导:-1+(H-h)*D/(x*x)
//导数等于0,求得极值x=sqrt((H-h)*D)
//影子在地面最长时x=(H-h)*D/H;
scanf("%d",&T);
while(T--){
scanf("%lf%lf%lf",&H,&h,&D);
double jz=sqrt((H-h)*D);
double ans;
if(jz<=(H-h)*D/H)ans=D-(H-h)*D/H;
else if(jz>=D)ans=h;
else ans=D-jz+H-(H-h)*D/jz;
printf("%.3lf\n",ans);
}
return ;
}
三分:
#include<stdio.h>
#include<math.h>
double H,h,D;
double getl(double x){
return D-x+H-(H-h)*D/x;
}
void sanfen(){
double l=(H-h)*D/H,m,mm,r=D;//l从地面最长开始
while(r-l>1e-){
m=(l+r)/;
mm=(m+r)/;
if(getl(m)>=getl(mm))r=mm;
else l=m;
}
printf("%.3lf\n",getl(l));
}
int main(){
int T;
scanf("%d",&T);
while(T--){
scanf("%lf%lf%lf",&H,&h,&D);
sanfen();
}
return ;
}
Light Bulb(三分)的更多相关文章
- ZOJ 3203 Light Bulb (三分+计算几何)
B - Light Bulb Time Limit:1000MS Memory Limit:32768KB 64bit IO Format:%lld & %llu Submit ...
- ZOJ - 3203 Light Bulb(三分)
题意:灯离地面的高度为$H$,人的身高为$h$,灯离墙的距离为$D$,人站在不同位置,影子的长度不一样,求出影子的最长长度. 思路:设人离灯的距离为$x$,当人走到距离灯长度为$L$时,人在墙上的影子 ...
- 三分 --- ZOJ 3203 Light Bulb
Light Bulb Problem's Link: http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3203 Mean: ...
- ZOJ 3203 Light Bulb (三分查找)
Light Bulb Time Limit: 1 Second Memory Limit: 32768 KB Compared to wildleopard's wealthiness, h ...
- A. Light Bulb
A. Light Bulb Time Limit: 1000ms Case Time Limit: 1000ms Memory Limit: 32768KB 64-bit integer IO f ...
- ZOJ 3203 Light Bulb - 求导求最大值
如果L全在地面上: 输出 h * D / H 如果L全在墙上: 输出 h 否则: (D - X ) / X = Y / (H - h) L = D - X + h - Y 然后对L求导即可 #incl ...
- zoj 3203 Light Bulb,三分之二的基本问题
Light Bulb Time Limit: 1 Second Memory Limit: 32768 KB Compared to wildleopard's wealthiness, h ...
- ZOJ 3203 Light Bulb
Compared to wildleopard's wealthiness, his brother mildleopard is rather poor. His house is narrow a ...
- ZOJ 3203 Light Bulb(数学对勾函数)
Light Bulb Time Limit: 1 Second Memory Limit: 32768 KB Compared to wildleopard's wealthiness, h ...
随机推荐
- HTML豆ちしき
HTML文档里所有的空白符(空格,Tab,换行,回车)会被浏览器忽略,唯一的例外是空格,对空格的处理方式是所有连续的空格被当成一个空格,不管有一个,还是两个,还是100个.之所以有这样的规则是因为忽略 ...
- Oracle EBS-SQL (SYS-10):锁定表查询.sql
/*死锁查询-1*/ SELECT o.object_name, l.session_id,l.process, l.locked_mode FROM v$locked_object l , dba_ ...
- java中输出流OutputStream 类应用实例(转)
OutputStream类该类是字节输出流的抽象类,定义了输出流的各种操作方法.这些方法的说明如表1所示.下面通过实例介绍如何使用OutputStream类向控制台输出字符串信息.步骤如下.(1)创建 ...
- sshuttle基于VPN的透明代理,安全连接
sshuttle基于VPN的透明代理, 通过 ssh 创建一条从你电脑连接到任何远程服务器的 VPN 连 sudo sshuttle -r username@sshserver 0.0.0.0/0 - ...
- spring mvc 使用jsr-303进行表单验证的方法介绍
源代码来源:http://howtodoinjava.com/spring/spring-mvc/spring-bean-validation-example-with-jsr-303-annotat ...
- UberX及以上级别车奖励政策(优步北京第二、三组)
优步北京第二.三组: 定义为2015年6月1日至7月19日激活的司机(以优步后台数据显示为准) 滴滴快车单单2.5倍,注册地址:http://www.udache.com/如何注册Uber司机(全国版 ...
- freemaker
FreeMarker模板文件主要由如下4个部分组成: 1,文本:直接输出的部分 2,注释:<#-- ... -->格式部分,不会输出 3,插值:即${...}或#{...}格式的部分 ...
- linux经常使用(一)linux 安装配置 jdk之 找不到安装文件文件夹及source /etc/profile 报unexpected end of file 错误 解决
linux 安装配置 jdk 应该算是一个非常主要的东西.可是我到如今才自己第一次 正式安装.果然出现了问题.. 问题就是 安装之后 找不到 安装路径 ,进而没法配置环境变量. 现象例如以下: 提示 ...
- Android 读取Assets中图片
bgimg0 = getImageFromAssetsFile("Cat_Blink/cat_blink0000.png"); * * 从Assets中读取图片 */ privat ...
- javaScript 工作必知(五) eval 的使用
eval eval(parse) parse :里面跟参数字符串,我们知道执行javascript 会编译执行, 改变全局变量的值: var x = 2; //定义的全局变量 alert(x); ...