hdu 4355 Party All the Time 三分
来源:互联网 发布:wpf高级编程 编辑:程序博客网 时间:2024/05/16 04:20
Problem Description
In the Dark forest, there is a Fairy kingdom where all the spirits will go together and Celebrate the harvest every year. But there is one thing you may not know that they hate walking so much that they would prefer to stay at home if they need to walk a long way.According to our observation,a spirit weighing W will increase its unhappyness for S3*W units if it walks a distance of S kilometers.
Now give you every spirit’s weight and location,find the best place to celebrate the harvest which make the sum of unhappyness of every spirit the least.
Input
The first line of the input is the number T(T<=20), which is the number of cases followed. The first line of each case consists of one integer N(1<=N<=50000), indicating the number of spirits. Then comes N lines in the order that x[i]<=x[i+1] for all i ( 1 < = i < N). The i-th line contains two real number : Xi,Wi, representing the location and the weight of the i-th spirit. ( |xi|<=106, 0< wi<15 )
Output
For each test case, please output a line which is “Case #X: Y”, X means the number of the test case and Y means the minimum sum of unhappyness which is rounded to the nearest integer.
Sample Input
1
4
0.6 5
3.9 10
5.1 7
8.4 10
Sample Output
Case #1: 832
Author
Enterpaise@UESTC_Goldfinger
Source
2012 Multi-University Training Contest 6
设该点坐标为x,,sum=(fab(x-x1))^3*w+(fab(x-x2))^3*w+(fab(x-x3))^3*w+…+(fab(x-xn))^3*w
对这个式子进行2次求导有..6(fab(x-xi))+1..恒大于0,,因此不满意度呈凹性。所以用3分。。
注意0.f已经四舍五入了。。不需要所谓的 rounded to the nearest integer.了。。(被坑一次)
fab(x)要耗时。。提出来。。。(少用)
#include<cstdio>#include<cstring>#include<algorithm>#include<cstdlib>#include<cmath>#define EPS 1e-5using namespace std;int n;double a[50005];double s[50005];double man(double x){ double sum=0.0; for(int i=1;i<=n;i++) { double t=fabs(x-a[i]); sum+=s[i]*t*t*t; } return sum;}int main(){ int T; scanf("%d",&T); for(int t=1;t<=T;t++) { scanf("%d",&n); for(int i=1;i<=n;i++) scanf("%lf %lf",&a[i],&s[i]); double l=a[0]; double r=a[n]; while(r-l>=EPS) { double d1=l+(r-l)/3.0; double d2=r-(r-l)/3.0; if(man(d1)<man(d2)) r=d2; else l=d1; } printf("Case #%d: %.0f\n",t,man(l+(r-l)/3.0)); } return 0;}
- HDU 4355 Party All the Time 三分
- hdu 4355 Party All the Time (三分)
- HDU 4355 Party All the Time 三分
- hdu 4355 Party All the Time 三分
- HDU 4355 Party All the Time(三分)
- Party All the Time+hdu+三分搜索
- HDU 4355 Party All the Time(三分)
- HDU 4355 Party All the Time(三分)
- HDU 4355 - Party All the Time(三分)
- HDU 4355 Party All the Time(三分|二分)
- hdu 4355 Party All the Time 典型三分
- HDU 4355 Party All the Time (三分)
- HDU 4355 Party All the Time(三分)
- HDU 4355 Party All the Time(三分精度问题)
- POJ 4355 Party All the Time(三分)
- [HDU4355][三分]Party All The Time
- HDU4355 Party All the Time (三分搜索)
- Party All the Time(三分)
- Android内存管理机制详解
- 员工管理系统
- 2014找工作总结-机会往往留给有准备的人
- VirtualBox快捷键
- 五校联考第一套第一式总结
- hdu 4355 Party All the Time 三分
- Linux分享之iptables:防火墙以及网络协议基本原理
- matlab读取/播放视频的函数(1)
- 我才不是萝莉控呢
- Android 自定义View流程
- xpath学习(一)
- 使用Putty连接Ubuntu虚拟机
- Android Service使用方法--简单音乐播放实例
- 【离散数学】实验二 集合上二元关系性质判定的实现