Assume the coasting is an infinite straight line. Land is in one side of coasting, sea in the other. Each small island is a point locating in the sea side. And any radar installation, locating on the coasting, can only cover d distance, so an island…

题意:在坐标轴中给出n个岛屿的坐标,以及雷达的扫描距离,要求在y=0线上放尽量少的雷达能够覆盖全部岛屿. 很明显的区间选点问题. 代码: /* * Author: illuz <iilluzen[at]gmail.com> * Blog: http://blog.csdn.net/hcbbt * File: l2911.cpp * Create Date: 2013-09-09 20:51:05 * Descripton: */ #include <cstdio> #include…

题目大意: 在X轴选择尽量少的点作为圆心,作半径为d的圆.使得这些圆能覆盖所有的点. 思路: 把每个点都转化到X轴上.也就是可以覆盖这个点的圆心的位置的范围[a,b].然后按照每个点对应的a从小到大排序.第一点需要特殊处理,我们赋值r=b0 .也就是使得第一个圆的圆心的横坐标尽量大.然后遍历剩下的点.对于i点,如果该点的ai大于r, 就需要增加一个圆,圆心为bi :否则的话,把r更新为r与bi中小的值. 代码: #include<iostream> #include<cstdio>…

Input The input consists of several test cases. The first line of each case contains two integers n (1<=n<=1000) and d, where n is the number of islands in the sea and d is the distance of coverage of the radar installation. This is followed by n li…

Radar Installation Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 54798   Accepted: 12352 Description Assume the coasting is an infinite straight line. Land is in one side of coasting, sea in the other. Each small island is a point loca…

解题思路:给出n个岛屿,n个岛屿的坐标分别为(a1,b1),(a2,b2)-----(an,bn),雷达的覆盖半径为r 求所有的岛屿都被覆盖所需要的最少的雷达数目. 首先将岛屿坐标进行处理,因为雷达的位置在x轴上,所以我们设雷达的坐标为(x,0),对于任意一个岛屿p(a,b),因为岛屿要满足在雷达的覆盖范围内,所以 (x-a)^2+b^2=r^2,解得 xmin=a-sqrt(r*r-b*b);//即为区间的左端点 xmax=a+sqrt(r*r-b*b);//即为区间的右端点 接下来区间选点即…

Radar Installation Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 20000/10000K (Java/Other) Total Submission(s) : 22   Accepted Submission(s) : 9 Problem Description Assume the coasting is an infinite straight line. Land is in one side of coa…

Radar Installation Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 54593   Accepted: 12292 Description Assume the coasting is an infinite straight line. Land is in one side of coasting, sea in the other. Each small island is a point loca…

Radar Installation Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 68578   Accepted: 15368 Description Assume the coasting is an infinite straight line. Land is in one side of coasting, sea in the other. Each small island is a point loca…

Radar Installation Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 106491   Accepted: 23648 Description Assume the coasting is an infinite straight line. Land is in one side of coasting, sea in the other. Each small island is a point loc…