点击打开链接题目链接 Qin Shi Huang's National Road System Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 5023    Accepted Submission(s): 1749 Problem Description During the Warring States Period of anci…

题目链接:传送门 题意: 有n坐城市,知道每坐城市的坐标和人口.如今要在全部城市之间修路,保证每一个城市都能相连,而且保证A/B 最大.全部路径的花费和最小,A是某条路i两端城市人口的和,B表示除路i以外全部路的花费的和(路径i的花费为0). 分析: 先求一棵最小生成树,然后枚举每一条最小生成树上的边,删掉后变成两个生成树.然后找两个集合中点权最大的两 个连接起来.这两个点中必定有权值最大的那个点.所以直接从权值最大的点開始dfs. 为了使A/B的值最大,则A尽可能大,B尽可能小.所以B中的边一…

先求出最小生成树,然后枚举树上的边,对于每条边"分别"找出这条割边形成的两个块中点权最大的两个 1.因为结果是A/B.A的变化会引起B的变化,两个制约.无法直接贪心出最大的A/B.故要通过枚举 2.无论magic road要加在哪里.加的边是否是最小生成树上的边,都会产生环,我们都要选择一条边删掉 注意删掉的边必须是树的环上的边.为了使结果最大.即找出最大的边 3.能够枚举两点.找出边,也能够枚举边,找出点,我是用后者.感觉比較easy写也好理解 #include <cstdio…

原题链接:http://acm.hdu.edu.cn/showproblem.php?pid=4081 Qin Shi Huang's National Road System Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5428    Accepted Submission(s): 1902 Problem Description…

Qin Shi Huang's National Road System Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) [Problem Description] During the Warring States Period of ancient China(476 BC to 221 BC), there were seven kingdoms in China ---…

Qin Shi Huang's National Road System Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3843    Accepted Submission(s): 1336 Problem Description During the Warring States Period of ancient China(47…

题目:Qin Shi Huang's National Road System Qin Shi Huang's National Road System Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2049    Accepted Submission(s): 746 Problem Description During the W…

During the Warring States Period of ancient China(476 BC to 221 BC), there were seven kingdoms in China ---- they were Qi, Chu, Yan, Han, Zhao, Wei and Qin. Ying Zheng was the king of the kingdom Qin. Through 9 years of wars, he finally conquered all…

Qin Shi Huang's National Road System Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5608    Accepted Submission(s): 1972 Problem Description During the Warring States Period of ancient China(47…

题目链接 http://acm.hdu.edu.cn/showproblem.php?pid=4081 题意 给出n个城市的坐标 以及 每个城市里面有多少人 秦始皇想造路 让每个城市都连通 (直接或者间接都可以) 然后 有一个特别厉害的大臣 可以造一条魔法路 不用耗费资金 但是要求 这条路链接的两座城市的人要尽量多 定义了一个 value = A/B A = 魔法路链接的两座城市的总人数 B = 除了魔法路,其他路的总权值 求出最大的value 思路 首先我会想到最小生成树 然后我想让value…