博客
关于我
POJ - 1106 Transmitters
阅读量:510 次
发布时间:2019-03-07

本文共 2845 字,大约阅读时间需要 9 分钟。

Transmitters

In a wireless network with multiple transmitters sending on the same frequencies, it is often a requirement that signals don’t overlap, or at least that they don’t conflict. One way of accomplishing this is to restrict a transmitter’s coverage area. This problem uses a shielded transmitter that only broadcasts in a semicircle.

A transmitter T is located somewhere on a 1,000 square meter grid. It broadcasts in a semicircular area of radius r. The transmitter may be rotated any amount, but not moved. Given N points anywhere on the grid, compute the maximum number of points that can be simultaneously reached by the transmitter’s signal. Figure 1 shows the same data points with two different transmitter rotations.

All input coordinates are integers (0-1000). The radius is a positive real number greater than 0. Points on the boundary of a semicircle are considered within that semicircle. There are 1-150 unique points to examine per transmitter. No points are at the same location as the transmitter.

Input

Input consists of information for one or more independent transmitter problems. Each problem begins with one line containing the (x,y) coordinates of the transmitter followed by the broadcast radius, r. The next line contains the number of points N on the grid, followed by N sets of (x,y) coordinates, one set per line. The end of the input is signalled by a line with a negative radius; the (x,y) values will be present but indeterminate. Figures 1 and 2 represent the data in the first two example data sets below, though they are on different scales. Figures 1a and 2 show transmitter rotations that result in maximal coverage.

Output

For each transmitter, the output contains a single line with the maximum number of points that can be contained in some semicircle.

Sample Input
25 25 3.5
7
25 28
23 27
27 27
24 23
26 23
24 29
26 29
350 200 2.0
5
350 202
350 199
350 198
348 200
352 200
995 995 10.0
4
1000 1000
999 998
990 992
1000 999
100 100 -2.5

Sample Output3

4
4

#include 
#include
#include
#include
#include
#include
using namespace std;struct Point{ double x, y; int k;};Point p[154];double X, Y, R;bool dis(double a, double b){ return (a - X) * (a - X) + (b - Y) * (b - Y) <= R * R ? 1: 0;}double crossangle(Point a, Point b){ return (a.x - X) * (b.y - Y) - (a.y - Y) * (b.x - X);}int main() { int n; while(scanf("%lf %lf %lf", &X, &Y, &R) != EOF) { if(R <= 0) break; scanf("%d", &n); for(int i = 0; i < n; i++) { double s, t; scanf("%lf %lf", &s, &t); p[i].x = s, p[i].y = t; if(dis(s, t)) p[i].k = 1; else p[i].k = 0; } int ans = 0; for (int i = 0; i < n; i++) { int aa = 0;/因为crossangle(p[i], p[i]) == 0 for(int j = 0; j < n; j++) { if(p[i].k && p[j].k && crossangle(p[i], p[j]) >= 0) aa++; } ans = max(ans, aa); } printf("%d\n", ans); }}

转载地址:http://wsbnz.baihongyu.com/

你可能感兴趣的文章
mysql 视图,视图更新删除
查看>>
MySQL 触发器
查看>>
mysql 让所有IP访问数据库
查看>>
mysql 记录的增删改查
查看>>
MySQL 设置数据库的隔离级别
查看>>
MySQL 证明为什么用limit时,offset很大会影响性能
查看>>
Mysql 语句操作索引SQL语句
查看>>
MySQL 误操作后数据恢复(update,delete忘加where条件)
查看>>
MySQL 调优/优化的 101 个建议!
查看>>
mysql 转义字符用法_MySql 转义字符的使用说明
查看>>
mysql 输入密码秒退
查看>>
mysql 递归查找父节点_MySQL递归查询树状表的子节点、父节点具体实现
查看>>
mysql 通过查看mysql 配置参数、状态来优化你的mysql
查看>>
mysql 里对root及普通用户赋权及更改密码的一些命令
查看>>
Mysql 重置自增列的开始序号
查看>>
mysql 锁机制 mvcc_Mysql性能优化-事务、锁和MVCC
查看>>
MySQL 错误
查看>>
mysql 随机数 rand使用
查看>>
MySQL 面试题汇总
查看>>
MySQL 面试,必须掌握的 8 大核心点
查看>>